It has been stated by Liu (2007) that
technically, it is quite challenging to create co-robot behaviour that works in
a deterministic and structured environment, co-robots have to operate in
stochastic and unstructured environments. The basic research question for being
addressed in this study was to make sure that co-robots function safely and
efficiently in uncertain environments. The concentration of the study has
actually been several things including setting up an analytical framework for
robot-human systems and establishing a methodology for designing a robot
behaviour for addressing the basic issue. A multi-agent system was introduced
by the author for modelling the robot-human systems. For addressing
uncertainties during robot-human interactions, a unique control and planning
architecture was introduced by the author, which a module of cognition for
human motion and behavior estimation, a long term planner for ensuring robot
efficiency, and a short-term planner for ensuring the safety of real-time under
different uncertainties which are present in the system (Liu, 2007).
The cognition module was further
discussed by Liu (2007), which involves online adaption and offline
classification of different human behaviours. Optimization problems’ optimal
control for long-term and short-term robot planning is covered in the study. Optimization
issues, in a cluttered environment, are non-convex and nonlinear, thus they are
quite tough to solve in real-time, which might delay the response of a robot in
emergency situations. Online rapid algorithms are created for handling problem:
CFS or algorithm of convex feasible set for optimization at long-term and SSA
or safe set algorithm for optimization at short-term. Particularly, non-convex
issue of optimization is transformed by the CFS algorithm into a set of issues
of convex optimization that can be resolved online, which converges in a few
iterations and also seems to run faster than conventional solvers of non-convex
optimization (Liu, 2007).
HRI’s current status was reviewed
by Sheridan (2016) together with present issues of research for the community
of human factors are explai9ned. It was concluded by the author that HR is an
evolving field. And specialized robots under teleportation of human have proven
effective in medical application and hazardous environments, as have
specialized robots under the supervisory control of human for space and
industrial tasks. Study in the areas of autonomous cars, intimate collaboration
with machines, human control over different robots, and social interaction with
them is still primate. Human robots’ efficacy still is not proven. Now, HRI is
applied in almost all tasks of robots including, military operations, policing,
package fetch, education, agriculture, surgery, undersea, aviation, space, and
manufacturing tasks (Sheridan, 2016).
In accordance with a study of Lasota
et al (2017), making sure that the safety of humans is a significant
consideration within the field of HRI. It doesn’t just include preventing
collisions among robots and humans operating in individual space, all possible ways
in which a person could be harmed should also be considered, ranging to adverse
psychological factors to physical contact which results from dangerous and
unpleasant interaction. This work collection was classified by authors into
four categories including psychological factors, prediction, motion planning,
and control safety. Recent work was discussed by authors in each of the
category, several sub-categories were identified, and discussed how these
methods can be utilized in improving the safety of HRI. Gaps in the present
studies were discussed by Lasota et al (2017) and future directions were
suggested for future work. By developing an organization field categorization,
it was hoped by authors for supporting future development and research of new
technologies for a safe interaction, along with facilitating the utilization of
these methods by authors in the community of HRI (Lasota et al, 2017).
In accordance with the research
of Yu et al (2015), different rehabilitation robots have direct interaction
with all humans. Actually, the control design is seemingly based on the model
of the actuator with consideration of the dynamics of interaction. It includes
compensation of human interaction, friction compensation, and is seemingly
enhanced with an observed of disturbance. In fact, such a scheme is capable of
enabling the robot in achieving impedance of low input while working in a mode
of human-in-charge and achieving accurate tracking of force when working in a
model of force control. Because of interaction with humans, the design of the controller
must also meet the requirement of stability. And the outcomes can be extended
to other assistive and rehabilitation robots which are driven with compliant
actuators without many issues (Yu et al, 2015).