The motion of a body segment is determined by joint torques and by the motions of the segments proximal or distal to it. This paper describes a threedimensional model that was used to determine the effects of the shoulder and elbow joint torques and of the upper trunk and arm motions on the angular accelerations of the arm segments during baseball pitching. Equations were developed to fractiona...

PURPOSE To observe various modes of lower limb locomotion, an inertial measurement unit (IMU) was used. Digital signals were used to identify signal characteristics that help to distinguish among locomotion modes and intensity levels. METHODS A wireless IMU was installed on the outside of shoes and three forms of locomotion (walking, running, and jumping) were assessed at two intensity levels...

Three-dimensional motion trajectories were computed, representing the motions that would be perceived by a perfect processor of acceleration information during the acceleration and deceleration stages of a centrifuge run. These motions serve as "baselines" for perceived self-motion in a centrifuge, and depend on the initial perception of orientation and velocity immediately preceding the accele...

A aberration, 949 aberrations, 947 absolute pressure, 368, 388 absolute zero, 431, 461 ac current, 711, 722 ac voltage, 711, 722 acceleration, 43, 75, 126, 153 acceleration due to gravity, 62, 75 accommodation, 931, 949 accuracy, 25, 31 acoustic impedance , 615, 620 active transport, 419, 419 activity, 1131, 1140 adaptive optics, 947, 949 adhesive forces, 377, 388 adiabatic, 515 adiabatic proce...

The six-degree equations of flight in their classic form do not provide a proper physical perception due to a number of interferences. Nor do they render visible the important role of attack angles. In this study, attempts have been made to develop a complete set of 3D acceleration equations from the equations of normal and tangential acceleration αN=vωv, αt=v ̇. For this purpose, a coordinate s...

Angular acceleration is an important parameter for status monitoring and fault diagnosis of rotary machinery. Therefore, we developed a novel permanent magnetic angular acceleration sensor, which is without rotation angle limitations and could directly measure the instantaneous angular acceleration of the rotating system. The sensor rotor only needs to be coaxially connected with the rotating s...

The paper reports an analytical model of a 4-DOF gyroaccelerometer consisting of 2-DOF drive and 2-DOF sense oscillators configured orthogonally. A detection scheme for time varying angular rate and linear acceleration, by combining the structural-model of gyro-accelerometer with the processes of synchronous demodulation and filtration, which leads to the inphase and quadrature components of th...

We examine the feasibility of designing an accelerometer-based (or gyroscope-free) inertial navigation system that uses only accelerometers to compute the linear and angular motions of a rigid body. The accelerometer output equation is derived to relate the linear and angular motions of a rigid body relative to a fixed inertial frame. A sufficient condition is given to determine if a configurat...

Shaft angular acceleration is one of the most important parameter of rotary machines, the error of angular acceleration increased when the shaft speed up. For this problem, a new high accuracy angular acceleration measurement system is presented, the principle of measurement is self-regulating the period of speed sampling signal according to the proportion of the shaft speed up. This measuremen...

We investigated the influence of vestibular stimulation with different angular accelerations and velocities on the perception of visual motion direction. Constant accelerations resulting in different angular velocities and constant angular velocities obtained at different accelerations were combined in twenty healthy subjects. Random-dot kinematograms with coherently moving pixels and randomly ...