EFFECTS OF SEAT POSITION ON JOINT LOADS OF THE UPPER EXTREMITIES DURING HANDCYCLING IN WHEELCHAIR-DEPENDENT INDIVIDUALS
The current study aimed to quantify the joint moments of the upper extremities with different seat positions during handcycling in wheelchair-dependent individuals. Sixteen subjects performed handcycling while the handgrip reaction forces were measured by a handgrip instrumented with a six-component load cell and body segment kinematic data by a motion capture system. Both data sets were used to calculate joint moments of the upper limbs during a crank cycle. The loads at the shoulder were affected mostly by the vertical seat positions. The higher the seat, the greater loads transmitted by the muscles with relatively greater strength. The current data will be helpful for future handcycle design and fitting for wheelchair-dependent individuals.
This paper addresses controller design for a follower aircraft (wingman) flying in tight cruise formation with a preceding aircraft (leader). The envisioned scenario is that of two similar commercial medium / large size freight or passenger aircraft in cruise flight. A VFW614 aircraft flying in the wake of another aircraft of the same type serves as example. A control design procedure for uncertain systems is used to obtain lateral and longitudinal controllers, yielding control loops with guaranteed robustness properties because wake vortex influence on the wingman is considered at modeling and design time in the uncertain system framework. In combination with appropriate references the resulting controllers are suitable for the three phases of formation flight: forming up, maintaining formation and leaving formation. Simulation results are presented.