Variant and invariant spatiotemporal structures in kinematic coordination to regulate speed during walking and running

Humans walk, run, and change their speed in accordance with circumstances. These gaits are rhythmic motions generated by multi-articulated movements, which have specific spatiotemporal patterns. The kinematic characteristics depend on the gait and speed. In this study, we focused on the kinematic coordination of locomotor behavior to clarify the underlying mechanism for the effect of speed on the spatiotemporal kinematic patterns for each gait. In particular, we used seven elevation angles for the whole-body motion and separated the measured data into different phases depending on the foot-contact condition, that is, single-stance phase, double-stance phase, and flight phase, which have different physical constraints during locomotion. We extracted the spatiotemporal kinematic coordination patterns with singular value decomposition and investigated the effect of speed on the coordination patterns. Our results showed that most of the whole-body motion could be explained by only two sets of temporal and spatial coordination patterns in each phase. Furthermore, the temporal coordination patterns were invariant for different speeds, while the spatial coordination patterns varied. These findings will improve our understanding of human adaptation mechanisms to tune locomotor behavior for changing speed

Development and Control of a Pneumatic Robot Arm for Industrial Fields

We developed a pneumatic robot arm driven by pneumatic actuators as a versatile end effector for material handling systems. The arm consists of a pneumatic hand and pneumatic wrist. The hand can grasp various objects without force sensors or feedback control. Therefore, this study aims to control the wrist motions to expand the hand motion's space. The hand mimics the human hand shape and can grasp objects that have different shapes and mechanical characteristics. The wrist has redundant degrees of freedom. This is useful when the robot moves to avoid obstacles. However, the drive mechanism of the wrist has nonlinearity from a mechanical viewpoint. Also, the pneumatic actuators used as the drive source have hysteresis characteristics. These features make the wrist motions difficult to control. Because the wrist is used in material handling systems, its motions need to be freely controlled. Therefore, in this research, experimental models of the drive system of the pneumatic robot wrist have been constructed. With the constructed models, the control systems were designed through simulations. After that, we attempted to control the wrist motions with the constructed controllers. As a result, the wrist models are coincident with wrist motions. Finally, experimental results were obtained that match the simulation results

The Influence of the Grip Acceleration on Club Head Rotation during a Golf Swing

Golfers aim to hit the golf ball correctly and maximize its displacement. It is necessary to predict shaft movement during a golf swing via simulation in order to determine the appropriate shaft for each individual golfer’s swing. Our previous study simulating golf club movement during the golf swing demonstrated 3D club movement via a finite element method simulation model with shaft flexibility. In this study, we added torque, taking into account the combination of grip acceleration and club head centroid, to the simulation model. In order to determine the influence of the torque, we then compared the measured and simulated results of shaft deflection and club head kinematics [HS (club head speed), Path (path angle), AA (attack angle), and FA (face angle)]. There was no significant torque influence for HS, AA, or shaft deflection. However, the Path and FA simulations were close to the measured values

Extracting golf-swing motions causing variations in shaft deformation behavior

Engineering of Sport 15 - Proceedings from the 15th International Conference on the Engineering of Sport (ISEA 2024) A judiciously selected golf club improvesshot performance and player sensory experience. Several studies explored golf swing dynamics and the consequent shaft deformation behaviors. A previous study reported shaft deformation differences due to club kick-point changes, subsequently impacting perceptual assessment. However, the relationship between perceptual assessment and swinging motion is obscure. To address this gap, the primary objective of this study is to analyze the mechanics of golf-swing motion. </p