This paper presents a modular architecture to develop a wearable system for real-time human motion capture. The system is based on a network of smart inertial measurement units (IMUs) distributed on the human body. Each of these modules is provided with a 32-bit RISC microcontroller (MCU) and miniaturized MEMS sensors: three-axis accelerometer, three-axis gyroscopes, and three-axis magnetometer. The MCU collects measurements from the sensors and implement the sensor fusion algorithm, a quaternion-based extended Kalman filter to estimate the attitude and the gyroscope biases. The design of the proposed IMU, in order to overcome the problems of the commercial solution, aims to improve performance and to reduce size and weight. In this way, it can be easily embedded in a tracksuit for total body motion reconstruction with considerable enhancement of the wearability and comfort. Furthermore, the main achievements will be presented with a performance comparison between the proposed IMU and some commercial platforms.

Категория: Ищем научные статьи | Нет комментариев »

Tele-operated robotics has been widely-used to manipulate heavy or hazardous objects in an unknown or dangerous environment. Nowadays, it is adopted in assistive robots to help the elderly in accomplishing household tasks. This paper proposes a hybrid control policy of robot arm motion to semi-automatically control a remote robot arm, which differs from previous work in its hybrid control policy. The motivations of the proposed hybrid control policy are rooted from (1) the safeness in controlling a robot arm in an uncertain environment by tele-operating the robot far from the target position; (2) the quickness in automatically controlling the robot arm close to the target position. By doing this, the robot arm is manipulated to quickly and safely reach to the target position. The proposed hybrid control policy tele-operates a robot by utilizing the joint angles of a human arm to remotely control the robot arm posture where the human joint angles are captured by the proposed motion capture method. To validate the proposed method, we conducted the experimental work on an 6 degree-of-freedom humanoid robot arm. The results showed that the human was able to safely and quickly reach to the manipulative objects by the proposed hybrid control policy of robot arm motion.

Категория: Ищем научные статьи | Нет комментариев »

We propose a realtime and direct-touch interaction system for 3D cultural artifact exhibition based on a texture-based haptic rendering technique. In the field of digital archive, it is important to archive and exhibit the cultural artifact at the high-definition. To archive the shape, color and texture of the cultural artifact, it is important to archive and represent not only visual effect but haptic impression. Therefore, multimodal digital archiving, realtime multisensory rendering, and intuitive and immersive exhibition system are necessary. Therefore, we develop a realtime and direct-touch interaction system for the 3D cultural artifact exhibition based on a texture-based haptic rendering technique. In our system, the viewer can directly touch a stereoscopic vision of 3D digital archived cultural artifact with the string-based and scalable haptic interface device «SPIDAR» and vibration motor.

Категория: Ищем научные статьи | Нет комментариев »

Muscle activation sensors are playing an important role in motion intention sensing of human-machine interaction system, such as human assisting manipulators or prosthetic devices. There are requirements of low-cost, reliability and portability for the device. This paper proposes an optical muscle activation sensor (oMAS) which measures the optical density in muscle by emitting and gathering the single wavelength light source. The oMAS was tested on the biceps brachii in isometric contraction condition, comparison with muscle activation level from surface electromyography. The results show that the optical density is enough to discriminable the muscle activation level. Therefore the oMAS is usable to measure the muscle contraction and it could offer a low-cost, reliable, portable and comfortable alternative for current muscle activation sensors.

Категория: Ищем научные статьи | Нет комментариев »

Video games can be mesmerizing, even for a rhesus monkey. Which may explain, in part, why 6-year-old Jasper has been sitting transfixed at a computer screen in a Washington University lab for nearly an hour, his gaze trained on a small red ball. A more interesting reason for Jasper’s quiet demeanor is that he is hurling the ball at a moving target using just his thoughts.

Категория: Ищем научные статьи | Нет комментариев »