International Journal of Humanoid Robotics

Previous studies reported that children with autism spectrum disorder (ASD) show a certain interest in social robots. This makes social robots potential to be a model to teach social skills. This exploratory study aims to investigate whether three types of joint attention skills (i.e., eye-contact, pointing, gaze-following) could be improved for five preschoolers with ASD using an evidence-based robot-modeling intervention with a humanoid social robot NAO. Our observation shows that these children were motivated when interacting with NAO by following and responding correctly to NAO’s joint attention behaviors. Although some improvements were found, no pattern or systematic effect could be revealed. In the future, more evidence-based studies are needed to investigate the benefits of robot-assisted therapy more deeply.

Lower limb exoskeletons have received considerable interest in strength augmentation, rehabilitation, and walking assistance scenarios. For walking assistance, repetitive and excessive foot-ground impact makes the patient uncomfortable and even leads to secondary damage. In this paper, variable stiffness ankles are used for collision reduction walking, based on which the Step Length-depended Variable Stiffness Planner (SLVSP) is proposed for lower limb exoskeletons. In the SLVSP, ankle stiffness and step length are optimized to reduce the Collision Loss Of Transport (CLOT). In addition, the mechanical energy-based human intention estimator for continuous walking by the SLVSP is proposed. A dynamics simulation verifies the method’s performance, and the results show that the proposed approach is effective.

Efficient and collision-free coordination of two robot arms is increasingly needed in various service-oriented robotic applications. This paper proposes a dual arm coordination algorithm to improve the efficiency of coordination by considering both robot’s actions and operating sequences of the tasks that need to use two arms to complete complex operations. Teleoperation demonstration is first performed to obtain the robot’s human-like motion trajectories, so as to reduce the probability of the collisions between the two arms. The coordination diagram in time domain is then designed to more clearly represent the situations of trajectory collisions and find the collision-free coordination action law. A Coordination Pair Generator (CPG) is designed to reorganize the operating sequences according to the characteristics of input trajectories and the action coordination. The effectiveness and efficiency of our method are verified on the simulation and physical experiments which execute the drug sorting task in nursing homes, respectively, on the ABB YuMi robot model and self-developed robot system. According to the experiment results, the operation time has been reduced by 9% and the collision area has been reduced by 7.5%.