An Intelligent Soft Exosuit for Hypogravity Adaptation

Human exploration of Mars represents the "next small step"[1] in the advancement of our
knowledge of the universe. Although several robotic and automated missions have been performed to
study the surface of the planet and its geological history, there simply is no substitute for the skills
and natural inquisitive character of a human being when it comes to the exploration of new environments. However, human exploration missions present several challenges and dangers to the human
body and its physiological functioning [2]. The journey to Mars itself will most likely be conducted in
microgravity, which has proven to cause loss of muscle mass, osteoporosis and arrhythmogenesis [1].

Additionally, landing on Mars will further challenge the motor control system because of the sudden
transition from the weightlessness of the space travel to the restored albeit reduced gravity (38% of
earth's gravity). What would be a simple injury on earth can then become a threat to the astronaut's
life and to the mission in the alien environment of Mars [3].

Lower body assistive devices have been designed for space applications to counteract the detrimental effects of microgravity on the astronaut's health, along with a daily excercise routine. Rigid
exoskeletons such as the X1 [4], were designed to enhance the excercise routine of International
Space Station (ISS) crewmembers, but could prove cumbersome to operate during daily tasks and
during Extra Vehicular Activities (EVAs). This is due to the fact that they require precise control of
the robotic joints, to allow smooth interaction with the user, and to their size and weight. Soft exosuits represent an attractive alternative solution to the challenges posed by space applications, thanks
to their inherent compliance, low weight, cost and power requirements. Devices like the Skinsuit [5],
that provides passive axial loading to simulate Earth's gravitational pull, were developed to address
muscle deterioration. However, it is still unclear whether this design is tolerable during ambulation or
daily task performance as it has only been tested for a limited amount of time during parabolic flights.
As such, a new type of soft exosuit, tailored to low, or hypo, gravity is required. We term such
a device a hypogravity exosuit, or HEXsuit. The predominant feature of the HEXsuit, which distinguishes it from other types of exosuits, will be the capacity of dynamically adapting the assistance
delivered depending on the astronaut's intention. The suit will adapt its characteristics (force, speed,
stiffness, resistance, assistance, etc.) according to the changing conditions and astronauts' demand
during the journey in microgravity, while exploring the surface of Mars (where gravity, although less
than Earth, is still significant) and during and after their return journey. This will be achieved by
means of embodied intelligence, i.e., the morphological features of the suit will provide the computational and sensing capabilities, allowing for a simpler external PID controller to be implemented.
The main morphological feature to be exploited for this application is the compliance of the
suit. Several designs of soft exosuits already exist for rehabilitation and performance augmentation
purposes. They are usually cable- or pneumatically-driven devices. While cable-driven devices present the most constrained behaviour of the two and can be made compliant through complex control
strategies, pneumatic actuators present high strength-to-weight ratio and are inherently compliant.

A recently proposed pneumatic actuator called the Bubble Artificial Muscle (BAM) [6] has particularly
high potential for use in such suits as it produces higher relative contractions than traditional McKibben actuators and operates at a lower pressure, thus increasing safety and the range of soft robotic applications.

FARSCOPE-TU will deliver a step change in UK capabilities in robotics and autonomous systems (RAS) by elevating technologies from niche to ubiquity. It meets the critical need for advanced RAS, placing the UK in prime position to capture a significant proportion of the estimated $18bn global market in advanced service robotics. FARSCOPE-TU will provide an advanced training network in RAS, pump priming a generation of professional and adaptable engineers and leaders who can integrate fundamental and applied innovation, thereby making impact across all the "four nations" in EPSRC's Delivery Plan. Specifically, it will have significant immediate and ongoing impact in the following six areas:
1. Training: The FARSCOPE-TU coherent strategy will deliver five cohorts trained in state-of-the-art RAS research, enterprise, responsible innovation and communication. Our students will be trained with wide knowledge of all robotics, and deep specialist skills in core domains, all within the context of the 'innovation pipeline', meeting the need for 'can-do' research engineers, unafraid to tackle new and emergent technical challenges. Students will graduate as future thought leaders, ready for deployment across UK research and industrial innovation.
2. Partner and industrial impact: The FARSCOPE-TU programme has been designed in collaboration with our industrial and end-user partners, including: DSTL; Thales; Atkins; Toshiba; Roke Manor Research; Network Rail; BT; National Nuclear Lab; AECOM; RNTNE Hospital; Designability; Bristol Heart Inst.; FiveAI; Ordnance Survey; TVS; Shadow Robot Co.; React AI; RACE (part of UKAEA) and Aimsun. Partners will deliver context and application-oriented training direct to the students throughout the course, ensuring graduates are perfectly placed to transition into their businesses and deliver rapid impact.
3. RAS community: FARSCOPE-TU will act as multidisciplinary centre in robotics and autonomous systems for the whole RAS community, provide an inclusive model for future research and training centres and bring new opportunities for networking between other centres. These include joint annual conference with other RAS CDTs and training exchanges. FARSCOPE-TU will generate significant international exposure within and beyond the RAS community, including major robotics events such as ICRA and IROS, and will interface directly with the UK-RAS network.
4. Societal Impact: FARSCOPE-TU will promote an informed debate on the adoption of autonomous robotics in society, cutting through hype and fear while promoting the highest levels of ethics and safety. All students will design and deliver public engagement events to schools and the public, generating knock-on impact in two ways: greater STEM uptake enhances future economic potential, and greater awareness makes people better users of robots, amplifying societal benefits.
5. Economic impact: FARSCOPE-TU will not only train cohorts in fundamental and applied research but will also demonstrate how to bridge the "technology valley of death" between lower and higher TRL. This will enable students to exploit their ideas in technology incubators (incl. BRL incubator, SetSquared and EngineShed) and through IP protection. FARSCOPE-TU's vision of ubiquitous robotics will extend its impact across all UK industrial and social sectors, from energy suppliers, transport and agriculture to healthcare, aging and human-machine interaction. It will pump-prime ubiquitous UK robotics, inspiring and enabling myriad new businesses and economic and social impact opportunities.
6. Long-term Impact: FARSCOPE-TU will have long-term impact beyond the funded lifetime of the Centre through a network for alumni, enabling knowledge exchange and networking between current and past students, and with partners and research groups. FARSCOPE-TU will have significant positive impact on the 80-strong non-CDT postgraduate student body in BRL, extending best-practice in supervision and training.