Advanced Robotics

doi: 10.1080/01691864.2013.855386pmid: N/A

Hasegawa, Yasuhisa; Oura, Saori; Takahashi, Junji

doi: 10.1080/01691864.2013.841311pmid: N/A

Patients with muscle weakness such as muscular dystrophy usually need someone’s assistance in their daily activities. In order to reduce the caregiver burden and to improve quality of life (QOL) of the patients, various robotic technologies have been developed. This paper presents an exoskeletal assistance system EMAS II for the patients, which assists the upper extremity for the purpose of daily activities such as eating, writing, or other desk works. The EMAS II assists four DOF; shoulder flexion-extension, shoulder abduction-adduction, shoulder medial-lateral rotation, and elbow flexion-extension. The EMAS II has three kinds of user interfaces which are operated by residual functions of the patients, because it is important for patients’ health and initiative to use the residual functions. In order to control the four DOFs exoskeleton system using the interfaces with less DOF, the EMAS II simulates upper limb motion patterns of healthy people. The patterns are modeled by extracting correlations between the height of the wrist joint and that of the elbow joint. Therefore, users have only to control the position of their wrist joint to do tasks at a table. Through an experiment with a healthy subject, the feasibility of meal assistance by the EMAS II was confirmed. Furthermore, the system was applied to a spinal muscular atrophy patient in a clinical trial to check the usability. The experimental results indicated that the EMAS II could support the patient’s upper extremity to do tasks at a table.

Owaki, Dai; Osuka, Koichi; Ishiguro, Akio

doi: 10.1080/01691864.2013.839087pmid: N/A

In this study, we discuss the stabilization mechanism underlying passive dynamic running (PDR), focusing on the feedback structure in an analytical Poincaré map. To this end, we derived a linearized analytical Poincaré map for PDR and analyzed its stability in terms of linear control theory. Through our theoretical analysis, we found that an ‘implicit two-delay feedback structure,’ which can be seen as a certain type of two-delay input digital feedback control developed as an artificial control structure for digital control, is an inherent stabilization mechanism in PDR appearing from a minimalistic biped model with elastic elements. To the best of our knowledge, this has yet to be addressed and studied. Our results shed new light on the principles underlying bipedal locomotion as ‘morphological computation.’

Taki, Shota; Handa, Yoichi; Hara, Naoyuki; Nenchev, Dragomir

doi: 10.1080/01691864.2013.839088pmid: N/A

This article focuses on the relation between workspace path geometry and the timing along the path, obtained via simple timing generators yielding constant end-link speed motion, natural motion, and two types of globally optimized joint velocity motions. The generators are designed within the Singularity-Consistent framework developed originally to tackle motion control in the vicinity of kinematic singularities. A comparative study highlights how performance expressed in terms of various kinematic and dynamic criteria of local (peak joint velocity and torque) and global (joint velocity/torque uniformity and total mechanical power) nature is influenced by the curvature of the path image in configuration space and by the vicinity of singular configurations. Results from simulations with a simple planar 2R limb and a spatial 3R positioning limb following linear and circular paths are presented.

Ha, Xuan Vinh; Ha, Cheolkeun; Lee, Jewon

doi: 10.1080/01691864.2013.839089pmid: N/A

Several optimization algorithms, such as the particle swarm optimization (PSO), genetic algorithm (GA), and ant colony optimization, have previously been applied in order to reliably obtain more accurate trajectory estimation for mobile robot. However, these optimization algorithms can get easily trapped in local optima when solving a complex system, which has many local optima and many input variables. This paper proposes a novel hybrid optimization algorithm-based tuning of the extended Kalman filter, which involves the PSO and mesh adaptive direct search algorithms, prior to operation. As demonstrated by our experimental results, the advantages of the novel hybrid optimization algorithm resolve the limitations of other algorithms in the trajectory estimation of a four track wheel skid-steered mobile robot (4-TW SSMR).

Lu, Huimin; Li, Xun; Zhang, Hui; Zheng, Zhiqiang

doi: 10.1080/01691864.2013.839090pmid: N/A

Topological localization is especially suitable for human–robot interaction and robot’s high level planning, and it can be realized by visual place recognition. In this paper, bag-of-features, a popular and successful approach in pattern recognition community, is introduced to realize robot topological localization. By combining the real-time local visual features proposed by ourselves for omnidirectional vision and support vector machines, a robust and real-time visual place recognition algorithm based on omnidirectional vision is proposed. The panoramic images from the COLD database were used to perform experiments to determine the best algorithm parameters and the best training condition. The experimental results show that the robot can achieve robust topological localization with high successful rate in real time by using our algorithm.

Mozos, Oscar Martinez; Mizutani, Hitoshi; Jung, Hojung; Kurazume, Ryo; Hasegawa, Tsutomu

doi: 10.1080/01691864.2013.839091pmid: N/A

This paper presents an approach to categorize typical places in indoor environments using 3D scans provided by a laser range finder. Examples of such places are offices, laboratories, or kitchens. In our method, we combine the range and reflectance data from the laser scan for the final categorization of places. Range and reflectance images are transformed into histograms of local binary patterns and combined into a single feature vector. This vector is later classified using support vector machines. The results of the presented experiments demonstrate the capability of our technique to categorize indoor places with high accuracy. We also show that the combination of range and reflectance information improves the final categorization results in comparison with a single modality.

Otsu, Kyohei; Otsuki, Masatsugu; Ishigami, Genya; Kubota, Takashi

doi: 10.1080/01691864.2013.843789pmid: N/A

Pose estimation is one of the important tasks for mobile robots exploring in outdoor environments. Recently, visual odometry has received a lot of attention since its localization is accurate even with low-cost sensors. Furthermore, the technique is not affected by wheel slips, and it can be performed without external infrastructures and preliminary maps. While existing techniques successfully provide good localization of outdoor vehicles, possible failures are not yet fully examined in untextured terrains where feature tracking occasionally fails. This paper proposes an approach to detect interest points from a wide variety of terrains by adaptively selecting algorithms. Experiments show that the approach provides robust and fast interest point detection even in untextured natural scenes.