Hideichi Nakamoto

Design of terrain adaptive versatile crawler vehicle HELIOS-VI

We are developing the HELIOS series, platforms for off-road vehicles and powered wheelchairs that are able to ascend and descend stairs. At present, we are developing an endless rotation locomotion type terrain adaptive vehicle HELIOS-VI that is propelled by 2 crawler belts. This vehicle has two continuously variable transmissions to change the velocity and direction of locomotion. The vehicle also has two active arms attached to the axis of the one drive pulley of the active crawler. One of the arms has two passive tires installed at its tip, and improves the vehicles terrain adaptability in rough terrain; the other arm carries payload and adjusts payload posture. We introduced a structure that can change the posture of this load dynamically. This paper first outlines development process of the HELIOS series, and then discusses the configuration of terrain adaptive crawler vehicle HELIOS-VI and the design of its driving mechanism.

Person Following Robot with Vision-based and Sensor Fusion Tracking Algorithm

Current demographics show that Japan is experiencing a combination of an aging population and a declining birth rate. Therefore, interest is growing in the potential of human symbiotic robots such as daily life support robots that can care for the aged and young children. Human symbiotic robots require sophisticated capabilities to achieve symbiosis and interaction with humans. It is essential for these robots to understand human intentions, and interact with humans and the environment. We call these technologies, which create real value for people and society, human-centric technologies, and have developed some home robots and human symbiotic robots (Yoshimi et al., 2004; Matsuhira et al., 2005a; Matsuhira et al., 2005b). The development of these robots is a typical target for human-centric technologies, but these technologies are not only applicable for robots but also for all machines that humans use. In the development of human symbiotic robots, we set one of the target criteria as the ability to recognize individuals using vision, and to understand situations in order to provide various real-life services to humans. To realize this target criterion, we think that the principal capabilities required are accurate vision and recognition of specified individuals who are in the vicinity. Moreover, another important capability common to the human symbiotic robot is that of moving safely near humans. In light of the above considerations, we have developed ApriAttendaTM shown in Fig.1, a person following robot that finds a specified person using visual tracking functions and follows him/her while avoiding obstacles (Yoshimi et al., 2006). Person following robots developed until now use various types of cameras for detecting a target person, and some of them use other sensors (Schlegl et al., 1998; Sidenbladh et al., 1999; Kwon et al., 2005; Cielniak et al., 2005; Kobilarov et al., 2006). Our newly developed robot adopts a stereo vision system, and additionally a Laser Range Finder (LRF) is mounted on the robot body to enhance the performance of person following motion. A person following robot has to distinguish the target object from other objects and recognize it by some methods. And the robot has to get the information of the target position, and continue following it quickly so as not to be left behind. At this time, camera information is often used to recognize the target. In addition, in the case of the stereo systems using two or more cameras, the distance information for the person following motion can be obtained. O pe n A cc es s D at ab as e w w w .ite ch on lin e. co m

Optimal load-sensitive control for mobile robots equipped with continuously variable transmissions

A continuously variable transmission (CVT) can be advantageously used to drive a robot in its most efficient operation region for a wide range of external loads. The paper describes an optimal load-sensitive control algorithm for an actuator unit comprising a CVT and an electric motor. The introduced control algorithm takes into account both the electrical motor and the CVT efficiency. The validity of the proposed method is demonstrated by simulations and experiments carried out on an actual stair-climbing mobile robot HELIOS-VI.

Person Following Robot ApriAttenda

We have developed the person following robot ApriAttenda(TM). This robot can accompany a person using vision based target detection and avoid obstacles with ultrasonic sensors. The robot first identifies an individual with its image processing system by detecting a persons region and recognizing the registered color and texture of his/her clothes. Our newly developed algorithm allows the robot to extract a particular individual from a cluttered background, and to find and reconnect with the person if it loses visual contact. Tracking people with vision was realized by systematizing visual and motion control with a robust algorithm that utilizes various characteristics of the image data. ApriAttenda(TM) has been exhibited at Aichi EXPO 2005, and its robust functions and smooth person following capability were successfully demonstrated.