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This paper aims to overcome some of the practical difficulties in assistive control of exoskeletons by developing a new assistive algorithm, called output feedback assistive control (OFAC) method. This method does not require feedbacks from force, electromyography (EMG) or acceleration signals or even their estimated values.

The presented controller uses feedbacks from position and velocity of the output link of series elastic actuators (SEAs) to increase the apparent integral admittance of the assisted systems. Optimal controller coefficients are obtained by maximizing the assistance ratio subjected to constraints of stability, coupled stability and a newly defined comfort measure.

The results confirm the effectiveness of using the inherent properties of SEAs for removing the need for extra controversial sensors in assistive control of 1 degree of freedom (1-DOF) SEA powered exoskeletons. The results also clearly indicate the successful performance of the OFAC method in reducing the external forces required for moving the assisted systems.

As the provided experiments indicate, the proposed method can be easily applied to single DOF compliantly actuated exoskeletons to provide a more reliable assistance with lower costs. This is achieved by removing the need for extra controversial sensors.

This paper proposes a novel assistive controller for SEA-powered exoskeletons with a simple model-free structure and independent of any information about interaction forces and future paths of the system. It also removes the requirement for the extra sensors and transforms the assistive control of the compliantly actuated systems into a simpler problem of position control of the SEA motor.

This paper aims to propose a novel balance-assistive control strategy for hip exoskeleton robot.

A hierarchical balance assistive controller based on the virtual stiffness model of extrapolated center of mass (XCoM) is proposed and tested by exoskeleton balance assistive control experiments.

Experiment results show that the proposed controller can accelerate the swing foot chasing XCoM and enlarge the margin of stability.

As a proof of concept, this paper shows the potential for exoskeleton to actively assist human regain balance in sagittal plane when human suffers from a forward or backward disturbing force.

Actuators for human-interactive robot systems require transparency and guaranteed safety. An actuation system is called transparent when it is able to generate an actuation force as desired without any actuator dynamics. The requirements for the transparent actuation include high precision and large frequency bandwidth in actuation force generation, zero mechanical impedance and so on. In this paper, a compact rotary series elastic actuator (cRSEA) is designed considering the actuation transparency and the mechanical safety.

The mechanical parameters of a cRSEA are optimally selected for the controllability, the input and output torque transmissibility and the mechanical impedance by simulation study. A mechanical clutch that automatically disengages the transmission is devised such that the human is mechanically protected from an excessive actuation torque due to any possible controller malfunction or any external impact from a collision. The proposed cRSEA with a mechanical clutch is applied to develop a wearable robot for incomplete paraplegic patients. To verify torque tracking performance and disengagement of the mechanical clutch, experiments were conducted.

As the effects of the gear ratio, N1, on the four control performance indexes are conflicting, it should be carefully selected such that the controllability and the output torque transmissibility are maximized, while the disturbance torque transmissibility and the mechanical impedance are minimized. When the four control performance indexes were equally weighted, N1 was selected as 30. Experimental results showed that the designed cRSEA provided good control performances and the mechanical clutch worked properly.

It is important to design the actuator so as to maximize the control performance in accordance with its purpose. This paper presents the design guidelines for the SEA by introducing four control performance indexes and analyzing how the performance indexes vary according to the change of design parameter. From the viewpoint of practicality, a mechanical clutch design method that prevents excessive torque from being transmitted to the wearer and an analysis to solve the locking phenomenon when using a worm gear are presented, and a design method of SEA satisfying both control performance and practicality is presented.

Simple and affordable systems are described to assist wheelchair users in steering their wheelchairs across sloping ground. The systems can be attached to many standard powered wheelchairs. Wheelchairs often steer by having two swivelling caster wheels but problems with this configuration occur when a wheelchair is driven along sloping ground because the casters can swivel in the direction of the slope. Gravity then causes the wheelchair to start an unwanted turn or ‘veer’ and the chair goes in an unintended direction. This situation is exacerbated for switch users, as switches cannot provide fine control to trim and compensate. Early experiments demonstrated that calibrating wheelchair controllers for straight‐line balance and optimising motor‐compensation did not solve this problem. Caster angle was selected to provide feedback to the wheelchair controllers. At the point when veer is first detected, a wheelchair has already begun to alter course and the job of the correction system is to minimise this drift from the desired course. A rolling road was created as an assessment tool and trials with both the test bed and in real situations were conducted to evaluate the new systems. The small swivel detector that was created could be successfully attached to caster swivel bearings. The new system was successful, robust and was not affected by changeable parameters. Although primarily intended for switch users, the methods can be applied to users with proportional controls.

Walking-aid exoskeletons can assist and protect effectively the group with lower limb muscle strength decline, workers, first responders and military personnel. However, there is almost no united control strategy that can effectively assist daily walking. This paper aims to propose a hybrid oscillators’ (HOs) model to adapt to irregular gait (IG) patterns (frequent alternation between walking and standing or rapid changing of walking speed, etc.) and generate compliant and no-delay assistive torque.

The proposed algorithm, HOs, combines adaptive oscillators (AOs) with phase oscillator through switching assistive mode depending on whether or not the AOs' predicting error of hip joint degree is exceeded our expectation. HOs can compensate for delay by predicting gait phase when in AOs mode. Several treadmill and free walking experiments are designed to test the adaptability and effectiveness of HOs model under IG.

The experimental results show that the assistive strategy based on the HOs is effective under IG patterns, and delay is compensated totally under quasiperiodic gait conditions where a smoother human–robot interaction (HRI) force and the reduction of HRI force peak are observed. Delay compensation is found very effective at improving the performance of the assistive exoskeleton.

A novel algorithm is proposed to improve the adaptability of a walking assist hip exoskeleton in daily walking as well as generate compliant, no-delay assistive torque when converging.

In this paper we describe a novel human machine interface system aimed primarily at those who have experienced loss of extremity motor function. The system enables the control of a wide range of assistive technologies such as wheelchairs, prosthetics, computers and general electrical goods at the ‘flick of a tongue’. This system could benefit a huge sector of people including those who have suffered a spinal cord injury, stroke or quadriplegia.The technology focuses on a unique hands‐free interface whereby users can issue commands simply by performing subtle tongue movements; these tongue motions are continually monitored by a small microphone positioned comfortably within the ear canal. Due to the physiological connections between these regions and the distinctive nature of the signals, these commands can be detected and distinguished allowing a control signal to be issued.This inexpensive device offers significant advantages over existing technologies by providing unobtrusive, hygienic control through natural tongue motion. New software has been implemented, achieving over 97% correct classification across four different tongue movements for seven test subjects. Feasibility of the system as an interface for a variety of devices is demonstrated through simulation studies including controlling a prosthetic manipulator and power wheelchair.

This paper discusses the opinions of people who use communication aids regarding the development of a voice input voice output communication aid (VIVOCA) using speech recognition technology. It uniquely combines the views of users of communication aids with those of speech and language therapists. Semi structured questionnaires were completed by 12 users of communication aids and 34 speech and language therapists discussed the concept of a VIVOCA in three focus groups. A thematic analysis of the information was carried out. Input, output and hardware requirements are discussed leading to specifications that therapists and users perceive would be required for a VIVOCA.

The purpose of this paper is to provide an overview of navigational assistive technologies with various sensor modalities and alternative perception approaches for visually impaired people. It also examines the input and output of each technology, and provides a comparison between systems.

The contributing authors along with their students thoroughly read and reviewed the referenced papers while under the guidance of domain experts and users evaluating each paper/technology based on a set of metrics adapted from universal and system design.

After analyzing 13 multimodal assistive technologies, the authors found that the most popular sensors are optical, infrared, and ultrasonic. Similarly, the most popular actuators are audio and haptic. Furthermore, most systems use a combination of these sensors and actuators. Some systems are niche, while others strive to be universal.

This paper serves as a starting point for further research in benchmarking multimodal assistive technologies for the visually impaired and to eventually cultivate better assistive technologies for all.

Based on 2012 World Health Organization, there are 39 million blind people. This paper will have an insight of what kind of assistive technologies are available to the visually impaired people, whether in market or research lab.

This paper provides a comparison across diverse visual assistive technologies. This is valuable to those who are developing assistive technologies and want to be aware of what is available as well their pros and cons, and the study of human-computer interfaces.

Accessible games, both for serious and for entertainment purposes, would allow inclusion and participation for those with disabilities. Research into the development of accessible games, and accessible virtual environments, is discussed. Research into accessible Virtual Environments has demonstrated great potential for allowing people who are blind to explore new spaces, reduce their reliance on guides and aid development of more efficient spatial maps and strategies. Importantly, Lahav and Mioduser (2005, 2008) have demonstrated that, when exploring virtual spaces, people who are blind use more and different strategies than when exploring real physical spaces, and develop relatively accurate spatial representations of them. The present paper describes the design, development and evaluation of a system in which a virtual environment may be explored by people who are blind using Nintendo Wii devices, with auditory and haptic feedback. The nature of the various types of feedback is considered, with the aim of creating an intuitive and usable system. Using Wii technology has many advantages: it is mainstream, readily available and cheap. The potential of the system for exploration and navigation is demonstrated. Results strongly support the possibilities of the system for facilitating and supporting the construction of cognitive maps and spatial strategies. Intelligent support is discussed. Systems such as the present one will facilitate the development of accessible games, and thus enable Universal Design and accessible interactive technology to become more accepted and widespread.

The purpose of this paper is to present a surgical robot for spinal fusion and its control framework that provides higher operation accuracy, greater flexibility of robot position control, and improved ergonomics.

A human‐guided robot for the spinal fusion surgery has been developed with a dexterous end‐effector that is capable of high‐speed drilling for cortical layer gimleting and tele‐operated insertion of screws into the vertebrae. The end‐effector is position‐controlled by a five degrees‐of‐freedom robot body that has a kinematically closed structure to withstand strong reaction force occurring in the surgery. The robot also allows the surgeon to control cooperatively the position and orientation of the end‐effector in order to provide maximum flexibility in exploiting his or her expertise. Also incorporated for improved safety is a “drill‐by‐wire” mechanism wherein a screw is tele‐drilled by the surgeon in a mechanically decoupled master/slave system. Finally, a torque‐rendering algorithm that adds synthetic open‐loop high‐frequency components on feedback torque increases the realism of tele‐drilling in the screw‐by‐wire mechanism.

Experimental results indicated that this assistive robot for spinal fusion performs drilling tasks within the static regulation errors less than 0.1 μm for position control and less than 0.05° for orientation control. The users of the tele‐drilling reported subjectively that they experienced torque feedback similar to that of direct screw insertion.

Although the robotic surgery system itself has been developed, integration with surgery planning and tracking systems is ongoing. Thus, the screw insertion accuracy of a whole surgery system with the assistive robot is to be investigated in the near future.

The paper arguably pioneers the dexterous end‐effector appropriately designed for spinal fusion, the cooperative robot position‐control algorithm, the screw‐by‐wire mechanism for indirect screw insertion, and the torque‐rendering algorithm for more realistic torque feedback. In particular, the system has the potential of circumventing the screw‐loosening problem, a common defect in the conventional surgeon‐operated or robot‐assisted spinal fusion surgery.