Attitude estimation is often a prerequisite for control of the attitude or orientation of mechanical systems. Current attitude estimation algorithms use coordinate representations for the group of rigid body orientations. All coordinate representations of the group of orientations have associated problems. While minimal coordinate representations exhibit kinematic singularities for large rotati...

This brief presents a nonlinear observer that performs range estimation as well gyro-bias by using velocity, angular rate, and bearing angle measurements from landmarks at unknown locations. The is proved to have semiglobal asymptotic stability, its performance verified in simulations on experimental data. demonstrated an unmanned aerial vehicle (UAV) with sensor setup consisting of camera, ine...

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 ...

Selective semicircular canal inactivation and three-dimensional eye movement recordings have been used to investigate the spatial organization of vestibular signals in the vestibulo-ocular reflex (VOR) of rhesus monkeys. In animals with one pair of semicircular canals inactivated, afferent activity no longer codes all spatial components of head angular velocity. if it were the activation patter...

Postural control is composed of the integration of vision, vestibular system, and proprioceptive sense along with the balanced control of the musculoskeletal system [1,2]. Muscle fatigue can be defined as the decrease in the maximum muscular strength production capacity due to high intensity or prolonged exercise during physical activity [3,4]. Most studies related to muscle fatigue and postura...