Landing is a challenging aspect of flight because, to land safely, speed must be decreased to a value close to zero at touchdown. The mechanisms by which animals achieve this remain unclear. When landing on horizontal surfaces, honey bees control their speed by holding constant the rate of front-to-back image motion (optic flow) generated by the surface as they reduce altitude. As inclination i...

Unmanned planetary landers to date have landed "blind"; that is, without the benefit of onboard landing hazard detection and avoidance systems. This constrains landing site selection to very benign terrain, which in turn constrains the scientific agenda of missions. The state of the art Entry, Descent, and Landing (EDL) technology can land a spacecraft on Mars somewhere within a very large land...

abstract introduction: identifying factors which cause the high incidence of acl is of great importance .the anterior shear forces are the primary mechanism of load sustained on the acl. during exercise, the activity of muscles and position of lower limbs may increase or decrease the anterior shear force. the purpose of this study is to investigate the relationship between the activity level of...

Human running at low and intermediate speeds is characterized by a greater average force exerted after 'landing', when muscle-tendon units are stretched ('hard landing'), and a lower average force exerted before 'takeoff', when muscle-tendon units shorten ('soft takeoff'). This landing-takeoff asymmetry is consistent with the force-velocity relation of the 'motor' (i.e. with the basic property ...

The NATO/PfP Interoperability and Re-use Study, NIREUS, is a thirteen-nation project to apply the High Level Architecture (HLA) to investigate multinational distributed simulation for system design and acquisition. The NIREUS test case concerns distributed simulation of Vertical Take-Off and Landing (VTOL) air vehicles landing on ships, initially focusing on Maritime Unmanned Air Vehicles (MUAV...

This paper presents a feasibility study of a vision-based autonomous approach and landing for an aircraft using a direct visual tracking method. Auto-landing systems based on the Instrument Landing System (ILS) have already proven their importance through decades but general aviation stills without cost-effective solutions for such conditions. However, vision-based systems have shown to have th...

The Entry, Descent and Landing System (EDLS) is one of the main system drivers for an interplanetary mission aiming at landing a payload on a planetary surface. It contains three main subsystems with distinct functions designed for the Entry, the Descent and the Landing phases. Each of these subsystems has specific constraints. The first objective of the EDLS is to land safely a payload with a ...

CONTEXT Researchers have suggested that large landing forces, excessive quadriceps activity, and an erect posture during landing are risk factors for anterior cruciate ligament (ACL) injury. The influence of knee kinematics on these risk factors has been investigated extensively, but trunk positioning has received little attention. OBJECTIVE To determine the effect of trunk flexion on landing...

Background and Aims: The accurate mechanisms of ankle instability cannot be assessed in the absence of reliable knowledge about ground reaction force (GRF) variables. The purpose of this study was to evaluate the test-retest reliability of GRF variables during forward and lateral jump-landing in volleyball players with functional ankle instability (FAI). Methods: Eighteen professional volle...