Motion Laboratory

At accident or disaster scenes, few private citizens are qualified to provide first aid before the arrival of rescue workers. Although the worldwide spread of automated external defibrillators (AEDs) has been extensive, they are still not being efficiently utilized. This study proposes a VR simulator through which first aid techniques and its principles can be learned. In our system, users learn how to operate AEDs, for example, compressing the chest during cardiac arrest situations. They virtually provide first aid using an AED on a mannequin by manipulating characters displayed in a virtual space. By pressing the chest during cardiac arrest situations, users can learn correct positions, strength, and tempo. The position is determined by the distance between the hand position and the correct place, and the strength is determined by the acceleration obtained from the controller; the tempo is determined by the motion's cycle. Awareness of first aid can be improved by visual and auditory sensory feedback based on the user's behavior. I evaluated the usefulness of our proposed system with 16 people who used it. About 80% answered that it provided useful opportunities for practicing first aid. However, some feedback described the system's operation as difficult and complained that its sensations differed from the reality of actual first aid situations.

This research clarifies the pedaling effect for a road bike operated by riders whose elbows are on the handlebars. I obtained by motion capture the following three pedaling forms and compared them; a normal sitting form, a sitting form while applying full power, and a sitting form with elbows on the handlebars. I calculated the back’s inclination, the hip joint angle, and the leg-opening angle from above as feature values. I also calculated the inclination of the back’s angle between the vector from the waist to the neck and the vertical upward vector. hip The joint angle is defined as the angle between vectors from the middle of the waist to the neck and from the waist to the knee. The feature values were calculated with five-cycle data and the three pedaling forms were compared. The riders produced more speed with improved stability by placing their elbows on the handlebars because their back’s inclination was smaller and their amplitude average was smaller than in the sitting form with full power. Their thighs opened outward when their body was inclined forward since the hip joint angle is limited due to its flexibility.

In this research, for the purpose of choreography creation support for beginners of psyllium dance, I developed a system for simulating choreography of psyllium dance using 3D motion data acquired by Kinect. Psyllium dance is composed of skills, and the user selects and reproduces the motions under different conditions by dividing the frequently used operation into the type of melody A melody, melody B melody and hook. Restrictions such as not being able to select the next selectable motion and the same motion at the time of selection of motion are provided for each part. In hook, when choosing a skill genre and skill name, the count number of those techniques was adjusted to 32 counts by dividing it into a skill that can select the last 8 counts out of 32 counts of motion and a skill that cannot select. In order to confirm the usefulness of this system, I asked 4 people who had been performing psyllium dance for 3 years or more and 2 beginners to use this system and evaluated. As a result, I confirmed that this system is suitable for creating a simple choreography.

This research supports the creation of animated pair performance for a form of Japanese martial arts called Shorinji Kempo. I develop a system that can create performance demonstrations by freely combining the basic actions acquired by motion capture and then simulating them with 3DCG. The system allows users to define the offensive or defensive movements of actors for each selected action and automatically inserts the motion changes required for the concatenation of techniques and compositions. To support the creation of performances based on defined rules, it limits the number of iterations of the basic actions and, for example, inserts bowing motions with praying-hand gestures into the performance's beginning and end. The utility of the system is evaluated by five participants who hold first-degree black belts in Shorinji Kenpo. Consequently, its usefulness is confirmed by several opinions of participants expressing a desire to further use the system. On the other hand, they also mentioned, as future work, the need to increase the number of basic actions and to reproduce the performance more smoothly.

In real-world pair performance of the martial art called Shorinji Kempo, an actor needs a partner. In addition, inexperienced persons hesitate to try this martial art because it requires guidance from an experienced practitioner. In this research, I develop a system that can simulate pair performance using virtual reality technologies to stimulate interest in inexperienced persons and to give them the necessary skills. This system allows users to control a virtual character's viewpoint and both of its hands by adopting the tracking feature of a head-mounted display (HMD) and Oculus Touch. Users face the opponent character in the virtual world and input actions such as punching and guarding by mimicking the animations displayed in their view one by one. This system determines whether the actions' input strength and angle are appropriate. Furthermore, the system implements a function that enables the opponent character to feed back an action corresponding to each input as well as a function that allows the user to preview the pair performance from a third-person perspective to better understand its flow. From the questionnaire results of 12 users who had experienced this system, about 70% responded positively to questions about operability. About 80% responded positively to questions about their depth of understanding of pair performance and the system's ability to stimulate their interest.

Due to the development of electronic games based on home-game machines and digital technologies, children have fewer opportunities to play with traditional toys. This system increases interest in the game of Carrom, which combines Billiards and Ohajiki, a traditional Japanese children's game. I developed a play-support system for Carrom that can be enjoyed interactively using leap motions. By gestures that are input using leap motions, users can flip coin-shaped pieces in a virtual space. This system calculates the piece's speed and direction from the user's gestures and reproduces collisions with other pieces by physical simulation. I introduced rules for the calculation of points and processing penalties so that users can play without knowing Carrom's detailed rules. To evaluate the system's operability and usefulness, 21 subjects played it and answered questionnaires, which confirmed that it effectively raised interest in Carrom. Unfortunately, problems were identified with the recognition method of the gestures for flipping the piece and its moving direction.

Most accidents involving children in Japan can be prevented by countermeasures based on parental awareness. In this research, I developed a VR simulator using HMD and a controller to increase the awareness of what causes indoor accidents in children. This system allows users to experience from an infant's viewpoint the following top five indoor accidents: falling from high places; falling over; collisions; accidental ingestion; and burns. For example, during coincident ingestions, our system identified collisions between objects and virtual hands and between hands and heads. If the object is small, it is judged to have been accidentally swallowed. Six subjects watched CG animation of five accidents. Three subjects positively evaluated how our system increased their awareness. Subject feedback also pointed out that commentary on the accidents and countermeasure methods must be improved.

It takes time to wear a Japanese kimono and takes time to get dressed. Few environments are also conducive for kimono-wearing experiences. This research's goal is to stimulate interest in Japanese kimonos. I developed a system that manipulates characters in virtual space using HMD and a controller to provide the experience of wearing them. Users can try Japanese calligraphy while wearing a kimono in a virtual world. If my hand pulls on the kimono's sleeve with CG model, the user can prevent the sleeve from getting dirty. A physical simulation can mend the sleeve based on the movement of the character's hand. The material of the sleeve is cotton, and it features a high expansion ratio as a characteristic. For a more realistic experience, when the sleeve makes contact with the desk, it can be prevented from slipping off. Ten people in twenties experienced our system and evaluated it. As a result, I confirmed that it effectively stimulated interest in kimonos. Unfortunately, the sleeve's appearance in VR space must be improved.

Interest in augmented reality (AR) technology has spread to educational and medical fields. I developed a learning support system for artificial limbs and related equipment using AR technology for students who plan to become physiotherapists. By capturing AR markers attached to artificial arms or legs by a camera on a smartphone, explanatory text and movies are superimposed and displayed on the artificial limbs. Information can be remembered that is related to actual objects. I implemented a function through which learners can record comments about artificial limbs on a server to share knowledge among learners as well as a function that displays additional new information by representing combinations of multiple parts of artificial limbs and equipment when multiple markers are simultaneously recognized by a camera. Six people experienced our system and answered questionnaires about its operability, group utilization, and learning support utilization. Although their feedback supported its usefulness for learning assistance with multiple markers, the comment function must be improved.

To raise worldwide interest in wearing Japanese kimonos, I developed an interactive system with which users can design kimono patterns that can be viewed with CG and human body animation. As pattern designs, I cut out motifs from kimono images so that users can design kimonos by selecting and arranging such pattern materials as well as the cloth’s color. By adapting the created design on the CG of kimonos, users can design kimonos themselves. For intuitive and interactive user operation, all the operations can be set at arbitrary timings, allowing all the design-creation steps to be reflected in the CG in real time. By reproducing the human body motions assigned to the CG, sleeve movement can be appreciated based on human body animation. I experimentally evaluated my system’s utility and received almost 90% positive feedback, confirming that it can increase interest in Japanese kimonos.

Although the popularity of motorcycle simulators has spread, most require large-scale equipment. I developed a motorcycle simulator that resembles an actual driving method using a gesture controller to get a virtual motorcycle-riding experience. The driving action is detected by an acceleration sensor from a gesture controller called MYO that is attached to the rider's right forearm. I assigned the rotation angle of the right forearm calculated from the acceleration sensor to the body and the CG motorcycle's steering wheel. The inclinations of the motorcycle body and the steering wheel's direction are changed by the speed as well as the angle. The motorcycle body gradually inclines in proportion to its speed, and the steering wheel's direction is less changed in inverse proportion to it. I conducted an evaluation experiment with two experienced motorcycle riders and five inexperienced riders. Their positive feedback suggests that our system can raise interest in motorcycle simulations. However, their negative feedback focused on its operability because the CG motorcycle tilted vigorously when the users turned.

With the progress made in motion-capture techniques, it has become possible to easily and accurately capture human motion of the whole body. The purpose of this study is to support the further development of techniques focusing on sports and dance. I have developed a system for visualizing the characteristics of human motion obtained through optical motion capture using 3DCG. The system allows users to freely select characteristics and body parts as well as the motion data to be visualized. It also allows users to create virtual markers from real markers and visualize their characteristics such as center of gravity. Furthermore, animations made using these markers can be projected on to the frontal plane. By displaying multiple human motions at the same time, this system allows users to compare data of the same person but from different time periods or to compare beginners with advanced practitioners. Using the system, we analyzed one classic ballet movement called arabesque obtained by a female dancer to compare over time. I confirmed that the angle of hip adduction and the lateral tilt of the pelvis increase with her training. In addition, we confirmed that the dancer kept standing on tiptoe while learning the core of the body backward. To evaluate the usefulness of the system, the examinees used the system with motion data from windmill throwing of a softball. From the results of questionnaires on the understandability of the different visualization methods, it was confirmed that use of a trajectory is the optimum method to understand the speed and position of human motion.

• S.Nakadaira, A.Soga, K.Oda, A System to Support Kinematic Analysis by Visualizing Human Motion with CG, IWAIT2019, 2019