Though it is well known that landing in an excessively inverted and plantar-flexed position commonly causes lateral ankle sprains, this landing motion has not been well studied for its effects on the knee joint. This study examines the effects of landing surface inclinations on knee kinematics during drop landing. Twelve recreational athletes performed five drop landings from an overhead bar wi...

Direct-lift micro air vehicles have important applications in reconnaissance. In order to conduct persistent surveillance in urban environments, it is essential that these systems can perform autonomous landing maneuvers on elevated surfaces that provide high vantage points without the help of any external sensor and with a fully contained on-board software solution. In this paper, we present a...

The surface material at the Surveyor 5 site is granular and slightly cohesive. Spacecraft footpads plowed trenches in this material as the spacecraft slid during landing. For a compressible soil model, a static bearing capacity of 2.7 newtons/cm •' gave best agreement with the observations. Static firing of the vernier engines against the surface moved surface particles; a crater 20 cm in diame...

The fine lunar surface material at the Surveyor 3 landing site has about 3 X 108-dyne/cm 2 cohesion, 35 ø angle of internal friction, 3 X 105-dyne/cm ' static bearing capacity. A small rock withstood a local pressure of 2 X 107 dynes/cm -ø. Soil strength and density increase significantly at depths of a few centimeters. Exposed surface has a considerably higher albedo than the material just bel...

Autonomous landing is a challenging problem for aerial robots. An autonomous landing manoeuver depends largely on two capabilities: the decision of where to land and the generation of control signals to guide the vehicle to a safe landing. We focus on the rst capability here by presenting a strategy and an underlying fast algorithm as the computer vision basis to make a safe landing decision. T...

BACKGROUND The incidence of anterior cruciate ligament injuries among dancers is much lower than that among team sport athletes and no clear gender disparity has been reported in the dance population. Although numerous studies have observed differences in lower extremity landing biomechanics between male and female athletes, there is currently little research examining the landing biomechanics ...

Landing gear is a structure that is mounted under the fuselage and helps the aircraft in takeoffs and landings. The most important duty of landing gear is the control of vibration exerted on the system through the shock absorber which is a common component to all the landing gear. Considering the importance of this issue, the necessity of investigating shock absorber with features such as high ...

This paper deals with the simulation of landing gear semi-active control for a small trainer aircraft in a multibody framework. The behavior of single passive landing gear drop test simulation models and of a complete aircraft landing simulation model, developed and implemented in the commercial multibody code ADAMS in previous works, is compared to the that of analogous models equipped with se...

Anterior cruciate ligament (ACL) injuries occur most commonly during non-contact situations, such as landing from a jump. Arm position has been shown to affect the loading of the lower extremity and therefore alter the potential injury risk. This study aimed to investigate the effect of arm position on lower extremity kinematics during single limb drop landings. Eight recreational American foot...

ai = time aircraft i lands after the preferred landing time Pi (i 1; . . . ; N) bi = time aircraft i lands before the preferred landing time Pi (i 1; . . . ; N) C = cost coefficient vector defined in the linear programming problem Ei = earliest landing time for aircraft i (i 1; . . . ; N) fi = penalty cost per unit of time if aircraft i lands before the preferred landing time Pi (i 1; . . . ; N...