A multi-stage design framework for the development of task-specific robotic exoskeletons

© 2015 IEEE. This work presents a multi-stage design framework for developing robotic exoskeletons suited for specific tasks, such as individualized exercises that meet the needs of patients undergoing physical therapy. The framework systematically develops the exoskeleton based on the required task space, represented by a set of limb poses which may be defined directly, or indirectly using means such as motion capture. The design process seeks to maximize the poses inside and surrounding the defined task space whilst ensuring additional criteria required to perform the task are satisfied. A case study demonstrates the framework applied to develop two variations of shoulder exoskeleton suited for two specific upper limb activities. Prototype exoskeletons based on the framework's outcomes were constructed, and their suitability for use in their intended tasks were evaluated

Upper body pose estimation utilizing kinematic constraints from physical human-robot interaction

In physical Human-Robot Interaction (pHRI), knowing the pose of the operator is beneficial and may allow the robot to better accommodate the human operator. Due to a large redundancy in the human body, determining the pose of the human operator is difficult to achieve in unstructured environments especially in human-robot collaborative operations where the robot often occludes the human from vision-based sensors. This work presents an upper body pose estimation method based on exploiting known positions of the human operator's hands while performing a task with the robot. Upper body pose is estimated using upper limb kinematic models alongside sensor information and model approximations to produce solutions that are biomechanically feasible. The pose estimation method was compared to upper body poses obtained using a motion capture system. It was shown to be able to perform robustly with varying amounts of available information. This approach is well suited in applications where robots are controlled using well-defined interfaces such as handlebars, operating in unstructured environments

Effect of external force and bimanual operation on upper limb pose during human-robot collaboration

During physical Human-Robot Interaction (pHRI) in industrial applications such as human-robot collaborative abrasive blasting, the operator often interacts with the robot using two hands, exchanging forces through handle bars. For the robot to provide appropriate assistance to the operator and for safe interaction, it would be benefficial for the robot to know the pose of the user. This problem is often challenging due to environmental factors, limited sensing capability in the environment and the robot, and redundancy of the human upper-limb. This paper presents experimental study on how two-hand interaction and force exchange affect the operators upper-limb pose, which can be characterized by swivel angle. The poses of ten subjects were recorded as they interacted with a collaborative robot. Differences in the adopted upper limb pose were analyzed with respect to factors such as unimanual versus bimanual operation, and the amplitude of interaction force between an operator and the robot. The results discovered that the the effect of bimanual operation on the upper limb pose differs between individuals and the magnitude of the force had a varying effect on the pose. The requirement of applying a force forward produced an overall lower swivel angle

Towards Smart Green Wall Maintenance and Wallbot Technology

The UN forecast of a 3 degree Celsius global temperature increase by 2100 will exacerbate excessive heat. Population growth, urban densification, climate change and global warming contribute to heat waves, which are more intense in high-density environments. With urbanisation, vegetation is replaced by impervious materials which contribute to the Urban Heat Island effect. Concurrently, adverse health outcomes and heat related deaths are increasing and heat stress affects labour productivity. More green infrastructure, such as green walls, is needed to mitigate these effects, however maintenance costs, OH&S issues and perceptions of fire risk inhibit take up. What if these barriers could be overcome by a green wallbot? This research examines the feasibility of integrating smart technology in the form of a Wallbot. The research design comprised two workshops with key stakeholders; comprising green wall designers and installers, green wall maintenance teams, project managers and building owners with green wall installations, horticulture scientists, designers and mechatronics engineers. The aim was to gain a deeper understanding of the issues affecting maintenance of green walls on different building types in New South Wales Australia to inform the design of a prototype robot to maintain green walls. The wallbot has great potential to overcome the perceived barriers associated with maintaining green walls and also fire risk and detection. If these barriers are addressed, other locations, such as the sides of motorways or rail corridors, could be used for more green wall installations thereby increasing mitigation of UHI. This innovation would be a welcome addition to smart building technology and property maintenance This is a pilot study and the sample of stakeholders attending the workshops was small, though experienced. The range of green walls is varied and it was decided to focus initially on a specific type of green wall design for the prototype wallbot. Therefore other types, and sizes, of green walls may suit other specifications of wallbot design. To date no robot exists that maintains green walls and this innovative research developed a prototype for trialling maintenance and inspection. To date no robot exists that maintains green walls. No study to date has assessed stakeholder perceptions and developed prototype wallbot technology

The Wallbot: A Low-cost Robot for Green Wall Inspection

The benefits of urban green infrastructure, such as attenuating the urban heat island effect and improving air quality, are widely accepted. Regardless, the uptake of green walls (i.e. vertical gardens) is low due to the high costs relating to maintenance and OH&S. These barriers to adoption may be mitigated by using robotics to inspect and maintain green walls. In this work we present the Wallbot, a robotic system to inspect, monitor and aid in the maintenance of green walls. In its current form the system comprises of affordable off-the-shelf components to keep the system cost low. Preliminary development of the system, results of initial tests and findings are presented. The system offers the chance to reduce OH&S issues and maintenance costs associated with green walls

The Green Wallbot

The need and demand for robotic technology to increase the uptake of green walls and facades whilst reducing OHS and maintenance costs is clear. The benefits of urban green infrastructure are widely accepted and include urban heat island attenuation, increased bio diversity, reduced carbon emission, biophilia effects, provision of spaces for social interaction, attenuation of rainwater flooding and improved air quality. With climate change and increasing temperatures a stark reality, resilience and liveability as well as sustainability are greatly enhanced through the adoption of Green Infrastructure (GI). Wallbot, a robotic installation to inspect, monitor and maintain green walls offers the chance to reduce OHS issues and maintenance costs associated with green walls

Human Preferences in Using Damping to Manage Singularities During Physical Human-Robot Collaboration

When a robot manipulator approaches a kinematic singular configuration, control strategies need to be employed to ensure safe and robust operation. If this manipulator is being controlled by a human through physical human-robot collaboration, the choice of strategy for handling singularities can have a significant effect on the feelings and impressions of the user. To date the preferences of humans during physical human-robot collaboration regarding strategies for managing kinematic singularities have yet to be thoroughly explored.This work presents an empirical study of a damping-based strategy for handling singularities with regard to the preferences of the human operator. Two different parameters, damping rate and damping asymmetry, are tested using a double-blind A/B pairwise comparison testing protocol. Participants included two cohorts made up of the general public (n=51) and people working within a robotic research centre (n=18). In total 105 individual trials were performed. Results indicate a preference for a faster, asymmetric damping behavior that slows motions towards singularities whilst allowing for faster motions away

The ANBOT: An Intelligent Robotic Co-worker for Industrial Abrasive Blasting

© 2019 IEEE. We present the ANBOT, an intelligent robotic coworker for physical human-robot collaboration. The ANBOT system assists workers performing industrial abrasive blasting, shielding them from the large forces experienced during this physically demanding task. The co-operative robotic system combines the strength and endurance of robots with the decision making of skilled workers. The inherent challenges in human-robot collaboration, combined with the difficult blasting environment required novel design decisions to be made and new solutions to be developed. These include an approach for handling kinematic singularities in a manner suitable for human-robot co-operation, estimating worker pose under poor visibility conditions, and an intuitive control scheme that adapts the robotic assistance based on the estimated strength of the worker. In this work we summarise the ANBOT system and present findings from preliminary site trials. The trials included several real industrial blasting tasks under the control of a skilled abrasive blasting worker who had no experience working alongside a robot. Results demonstrate the suitability of the ANBOT for practical industrial applications