Robotic Exoskeletons Deliver Real Super Powers for Real People

Becoming super powered doesn’t require being born on a distant world or being bitten by a radioactive spider any more. With just a little help from a friendly neighborhood robotic exoskeleton, super powers are now within our grasp. Don’t get your hopes up for heat vision, flying or invisibility however, but super strength and super endurance are available today, and super speed is on the way.

Robotic exoskeletons provide normal humans with remarkable abilities by adding external reinforcement, often shaped similarly to bones but composed of metals or other rugged materials. These external skeletons mimic the regular movements of an arm or a leg, but with much more force, speed and precision. Several super powers are possible with robotic exoskeletons, so let’s look at a few of them in more detail.

Super Strength

Super strength is perhaps the most obvious super power that a robotic exoskeleton can provide. With steel reinforced arms and legs a mere human can lift many times their weight easily and efficiently. The ability to easily lift heavy loads has a wide range of applications. One application perhaps worthy of the use of super strength would be as part of a rescue operation to save people trapped under a collapsed building. A robotic exoskeleton, controlled by a trained human operator can move heavy rubble with much more precision than a familiar back hoe or earth mover. This unique combination of strength and controllability makes a robotic exoskeleton much more effective than traditional heavy equipment. In these applications raw strength is less of a requirement, so natural aptitude, experience in similar situations, and precision are more important. Perhaps dancing ability will become a key requirement when robotic exoskeleton operators are being selected.

Super Endurance

Another super power that robotic exoskeletons can deliver is the ability to do repetitive operations over long periods of time without tiring. Operating heavy portable tools or equipment, for example, can be done for much longer periods, with robotic exoskeleton assistance. This allows operators to use larger and heavier machines with their strength augmented by a powerful robotic exoskeleton, making the machines seem practically weightless to the human operator. These larger machines can be used for longer periods of time, since they seem weightless to the operator, and can replace the smaller portable machines non-augmented operators need to use. For example, a portable grinder or buffer might be limited to only a 4-inch surface, while an augmented operator might be able to use a machine that covers a 10-inch surface. This allows the operator to cover much more surface and with more precision, if the robotic exoskeleton can provide for finer control of the grinder than a non-augmented operator.

Robotic exoskeletons can also provide the human operator with the ability to easily perform repetitive operations. The human operator might put the exoskeleton in a training mode where the robotic controller can learn proper techniques while the human operator is engaged in a task. Once sufficiently programmed, the robotic controller could ‘take over’, in an auto-pilot mode while the human operator sits back and watches for exception conditions. The human operation would operate in training mode to handle the exception, and the robot would then have a new technique it could apply when in auto-pilot. Perhaps the operator would have a team of robotic assistants that could run on autopilot and the operator would ‘switch in’ to handle the difficult bits. Multi-taking at its most efficient. Of course, this would require significant operator skill and experience, but it is certainly a possibility, and one that many video game enthusiasts might already be trained for.

Super Speed

The ability to control an exoskeleton need not limit movements to only those the human operator can make. The robot’s controller could actually move the exoskeleton at speeds faster than humanly possible. Super speed can be applied to repetitive movements such as hammering or cutting. More complex motions like walking, running or climbing takes considerable skill and experience. Closing the familiar feedback loop we are all used to when walking or running, at an accelerated speed, might give the untrained operator dizzy spells and headaches, but with sufficient training true super speed might be accomplished. Perhaps in just a few years we will see robotic runners competing in the high hurdles, breaking records left and right. Robotic assistance for horses in the steeplechase might be a bit further off however.

Materials

These super powers don’t need fancy new alloys or exotic materials. Sure, stronger and lighter materials are always being developed and will find new applications, but much of the promise of super capabilities are available using standard materials found in existing applications. You won’t be lifting ocean liners, but you will be able to lift cars (even a car jack can do that, right) by just using the common stainless steel alloys used in many industrial applications. If you really need a less weighty implementation, look no further than your local bike shop. Carbon (High-Tensile) steel, chromoly (chrome molybdenum steel), aluminum, titanium and carbon fiber are all used in light weight bike frames.

Steel is probably the go-to material for most exoskeletons where raw strength is most important. It is also long lasting and very robust. Chromoly has both good strength and good flexing properties. If an exoskeleton needs less raw strength, but more flexibility and responsiveness chromoly might be the way to go. Many robotic exoskeletons will use more than one material. For example, legs and associated support elements might use stronger and heavier materials while arms would use lighter materials.

Controlling a Robotic Exoskeleton

The control system for a robotic exoskeleton will need some fairly heavy duty processing if it is to learn from the human operator. Depending upon the application, the processing power required to create autonomous movement, in real time (or with super speed in faster than real time) could be considerable. Real time data from sensors that provide guidance on balance, proximity, environmental conditions, as well as integrity of the robotic exoskeleton, all need to be processed by the command controller to determine the most efficient and safest autonomous operations. If learning modes are engaged the algorithms that sort through a large set of possible operations based on the current task and conditions will need to access massive amounts of data, preferably stored locally using robust flash memory, since hard disc drives may not be an option for robotic exoskeletons operating in harsh environments experiencing excessive amounts of vibration.

The control of the motors used to move the arms and legs also requires considerable processing power. Suitable processors include the ADSP-CM40 Family of Mixed Signal Controllers from Analog Devices. The CM40 is a 240MHz ARM Cortex-M4 processor with extensive support for the type complex signal processing algorithms used for robotic exoskeleton control. Modern motor control firmware can use advanced algorithms designed to improve efficiency, reduce wear, limit vibration and extend operating lifetime. Additionally, fail safe algorithms to prevent motors from burning out would be of critical importance. In fact, protecting the human operator from themselves could be the most important aspect of controlling a robotic exoskeleton successfully. Predicting the results of a movement that might unbalance the operator, overstress a support element or damage an actuator would be a ‘must have’ for any robotic exoskeleton with a large degree of motion, or locomotion.

A variety of motor control algorithms are available to choose from and each have significant advantages and disadvantages. For applications where raw strength is critical, high torque may be more important than efficiency. Perhaps a tried and true brushless DC motor is a good fit here. If precision and speed are more important a stepper motor might be a better fit. The availability of motor control development kits, libraries and configuration wizards for the system control microcontroller can make this part of the control design very efficient. An excellent article on motor control for robotics applications can be found in this Mouser Electronics hosted article, Considerations in Choosing Motors for Robotics.

Connectivity

You might be wondering how all the actuators, controllers and sensors needed to create this engineering marvel are going to communicate. The environment a robotic exoskeleton will be operating in may provide some clues as to what connections are most effective. For example, in a noisy or hostile environment wireless connectivity might not be a good choice. Noise could slow communications dramatically or even introduce errors. A robotic exoskeleton that uses hard wired connections is probably the most robust. If the exoskeleton is to be exposed to significant dirt, dust, rain and mud as well as significant vibration and stress, the connections need to be as robust as possible. In noisy environments fiber optic connections for high speed and robust data communications might even be possible. Power connections need to use traditional wired technology, but can benefit from the use of robust connections, protected wiring headers and housing. A full range of connectors for traditional interfaces such as USB and Ethernet as well as fiber optics and power connectors are provided by Molex and are found on Mouser.com.

Applications for Robotic Exoskeletons

Robotic exoskeletons that provide super strength, super endurance and/or super speed will be used for many more tasks than loading freight on a space ship or fighting acid spitting aliens. The previously mentioned use in rescue operations is just one life saving application. Think of the possibilities for other emergency response situations such as firefighting, floods or chemical spills where the exoskeleton could also provide environmental protection. Carrying heavy firefighting equipment to quickly and efficiently extinguish fires is clearly a lifesaving application, both for the disaster victims and the responders. During a flood, robotic-enhanced responders could quickly build barriers and save stranded flood victims. Responding in toxic environments with chemicals or radiation is also a possibility, but only if the exoskeleton can adequately protect the operator and the electronics. These toxic environment applications might be best addressed with a robot that is remotely operated, rather of a human operator. Even a super human has their limits.

Robotic exoskeletons can also be used to provide movement to those too paralyzed or injured to move on their own. Intelligent control can even learn from the operator and provide a range of autonomous activity. Walking, running or climbing could be accomplished semi-autonomously without the need to control individual ‘low level’ motions. Research is also opening up the possibility of movement controlled by measurements of brain wave activity. This approach can allow a significant level of operator control when combined with deep learning algorithms and autonomous control. While we are not yet able to build systems capable of reading the operators thoughts, research continues and perhaps this isn’t really that far off. Restoring this level of autonomy is another lifesaving application for robotic exoskeletons.

Conclusion

Super powers are available today through the use of robotic exoskeletons. Intelligent control systems that can provide a new level of autonomy will give these powers a significant boost, making it possible for even ordinary humans to control super strength, super endurance and super speed. Robotically-enhanced humans will be able to perform heroic deeds, in the real world, saving lives in disasters areas. Some of these heroes may even be those previously injured in rescue operation, with restored and enhanced abilities to continue to save lives in dangerous situations.

About the Author

Warren Miller is a contributing author at Mouser Electronics with over 30 years of experience in the electronics industry. He has had roles in product planning, applications, marketing and management for large established companies as well as startups. Currently he is President of Wavefront Marketing, a consultancy serving semiconductor, tools and intellectual property companies.

About Mouser Electronics