The present paper addresses the problem of analyzing the work of forklift trucks. To solve the problem, a forklift truck working model based on a state transition model is constructed using human activity sensing data, where the key point is using forklift truck operating data to determine human intention. The novel contribution of the model is its use of data that express the intention of the forklift truck operator to categorize the work of the forklift truck. By using a graph model, the proposed method can be extended to analyzing the human characteristics of forklift truck work. With this technique, some features of the graph model can be used to distinguish the skill level of the forklift truck operator.

This paper reports the development and evaluation of a simulated environment to perform autonomous tasks using LentiMark augmented reality marker-based pose estimation. Performance of marker-based pose estimation is evaluated in simulation over conditions such as position with respect to camera, yaw and roll of marker, varying illumination and shadow, motion blur and marker occlusion. While results will not directly translate to real world performance, limitations in the marker system's pose estimation accuracy due to pixelisation effects, detection failure due to background confusion under roll, and performance degradation with any marker occlusion are identified.

For an evaluation of walking motions, a body acceleration is considered to be an important measure. The reason is that, if the walking motion is stable, the body acceleration usually shows almost periodic patterns, and if not, it does not. Therefore, it is thought that, for an evaluation of crutch walking motions, the crutch user's body acceleration would be required. That is, unstable crutch walks result in aperiodic body accelerations, and it may cause the users falling. In this research, an instruction system of a crutch walking for untrained patients has been developed. The body accelerations are usually measured by acceleration sensors being attached on the walker's body. Therefore, the sensor systems may disturb smooth walking motions. In addition, it is desirable that commonly available sensors can be utilized for measurements of the walker's body accelerations without anything attached on the body. Therefore, in this paper, a novel acceleration measurement method, i.e., a body-part movement-based acceleration measurement method, was proposed for crutch users. For this purpose, several participants' crutch walks were measured by both an optical motion capturing system and an acceleration sensor system, and multiple linear regression analyses were applied for the acceleration data. As a result, an estimation model with the body acceleration was derived.

Up to now, several kinds of walk assisting devices have been developed, and these have been usually used by injured patients. Patients who have their leg injured often use crutches in order to reduce their weight to be borne with their injured leg, because crutches are regarded as familiar devices. However, some patients who were injured by sudden accidents don't know about proper methods to use the crutches, which results in improper usages: the improper usage may cause the patients to fall down, and it sometimes leads to more serious injuries. For these patients, it is effective to evaluate if the patient's method to use the crutches is proper or not based on the measurements of the walk motions in early rehabilitation stage. In addition, the walk motions had better been measured in a simple way rather than using complex measurement devices. In this paper, relationships between improper crutch walk and motions of participant's body parts were discussed, and its result is expected to be utilized to show which body part is most influenced by the improper crutch walk. In crutch walk experiment, motions of participants' thigh, knee and toe, body acceleration and tilting angle of the crutch were measured. As a result, especially, the motion of thigh was most influenced by the improper crutch walk. From this result, it was confirmed that crutch walks can be evaluated by measuring only the motion of thigh. This result may also show that thigh performs a crucial function for preventing falling in crutch walks.

Thousands of individuals of all ages are living with a spinal cord injury as a consequence of a traffic, or sports accident or other calamity, and many of these individuals incurred a C5-level spinal cord injury, with a loss of the ability to use their legs and exert extension force from the elbow joints. Many of the motions that are necessary in daily life are difficult or impossible to perform with this level of spinal cord injury, and it is expected that wearable motion-assist robots will someday be available for use by individuals with C5 injuries. In order to be wearable, an assist robot must not limit the user's range of motion while being used, and it must be suitable for a wide range of situations. In the present study, we developed an extension force support system that acts in accord with the operator's intentions under the effect of external force as the operator use a wearable motion-assist robot for an upper limb. The effectiveness of the developed system was demonstrated experimentally.

We proposed a synthetic aperture GPR (Ground Penetration Radar) for buried flat-plates. The geometrical conditions of the flat-plates, i.e., the length, the inclination angles, the horizontal positions, and the buried depth are estimated by using a nonlinear least-squares method: the geometrical model-calculated propagation times are fit to the observed ones at all the antenna positions. We carried out some survey experiments to inspect a metallic plate being buried in soil medium, and, furthermore, compared the proposed algorithm with a visual observation-based method. As a result, we confirmed the effectiveness of the proposed algorithm.

When a robot is operated remotely, a monitoring camera is often used. In conventional systems, an operator controls both a robot and a monitoring camera. A camera has to be controlled so that its zooming scale and angle are to be desirable for an operator. Therefore, the automatic control of a camera is necessary for smooth operations of a robot. In this paper, the authors proposed a new algorithm to control a monitoring camera automatically. While an operator sends commands to an operated manipulator via a joystick, a monitoring camera is automatically controlled based on the algorithm where the joystick motion information is ingeniously utilized. Experiments were carried out, and an effectiveness of the proposed algorithm was confirmed

The linear-actuated parallel mechanism that changes the motion characteristic according to the actuator configuration is known. The authors previously (2000) reported on the kinematics and the motion characteristic on the basis of the motion transmissibility. In this report, we analyze the changed in motion characteristics using the measures of manipulability. Indices of manipulability are given with components of the value determined by the singular value decomposition. The typical index is a volume of the manipulability ellipsoid. We clarify the features of the motion characteristics according to a change in the actuator configuration using these indices. Finally, we show the recommended application examples that are designed for mechanisms using the obtained result.

It is our purpose to develop an underwater microrobot that has the characteristics of flexibility, driven by a low voltage, good response and safety in body. In this paper, we propose a new prototype model of an underwater microrobot utilizing ionic conducting polymer film (ICPF) actuator as the servo actuator. The fish-like propulsion using ICPF actuator as a propulsion tail fin for a microrobot swimming structure in water or aqueous medium is developed. The overall size of the underwater microrobot prototype shaped as a boat with a pair of fins is 40 mm in length, 10 mm in width and 2 mm in thickness. The characteristic of the underwater microrobot is measured by changing the frequency of input voltage from 0.1 Hz to 5 Hz. The experimental results indicate that the swimming speed of the proposed underwater microrobot can be controlled by changing the frequency of input voltage.