It is well known that the linear feedback of the quar-ternion of the attitude error and angular velocity globally stabilizes the attitude of a rigid body. In this note, we show that the angular velocity feedback can be replaced by a nonlinear lter of the quaternion, thus removing the need of direct angular velocity measurement. In contrast to other approaches, this design exploits the inherent ...

This article provides reasoning and research of spatial mechanisms. The creation the first simple Bennett mechanism obtained through pyramid its base sides is described. In pyramid, angles inclination heights are determined to obtain standard equalities. Thanks all parameters, theoretical link lengths that have practical values determined. All parameters length presented on structural diagram f...

We present self-consistent numerical simulations of the sun’s convection zone and radiative interior using a two-dimensional model of its equatorial plane. The background reference state is a one-dimensional solar structure model. Turbulent convection in the outer convection zone continually excites gravity waves which propagate throughout the stable radiative interior and deposit their angular...

The force exerted by a muscle is a function of the activation level and the maximum (tetanic) muscle force. In "maximum" voluntary knee extensions muscle activation is lower for eccentric muscle velocities than for concentric velocities. The aim of this study was to model this "differential activation" in order to calculate the maximum voluntary knee extensor torque as a function of knee angula...

Single-unit activity in area M1 was recorded in awake, behaving monkeys during a three-dimensional (3D) reaching task performed in a virtual reality environment. This study compares motor cortical discharge rate to both the hand's velocity and the arm's joint angular velocities. Hand velocity is considered a parameter of extrinsic space because it is measured in the Cartesian coordinate system ...