• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.1
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• pp.81-87
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• 2015

In order for a Power Assisted Wheelchair (PAW) to maintain a straight driving direction, the same force must be delivered to both wheels. However, a human has different strength between the right and left arms, and cannot control the force uniformly at all times. Therefore, appropriate assist torque shall be generated from unbalanced human torque inputs by detecting the user intention, in order to maintain direction uniformly in straight sections or change direction quickly in curved sections. In this study, a special function is proposed to detect the intention of drivers on the basis of temporal similarity between the input torque signals, and a torque balancing technique based on this function is proposed. In the experiments, the effectiveness of the proposed torque balancing method are verified.

• Journal of Biosystems Engineering
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• v.35 no.5
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• pp.302-309
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• 2010

Aerial application using an unmanned agricultural helicopter would allow precise and timely spraying. The attitude of a helicopter depends on a number of dynamic variables for roll-balanced flight. Laterally tilting behavior of a helicopter is a physically intrinsic phenomenon while hovering and forwarding. In order to balance the fuselage, the rotor should be counter-tilted, resulting in the biased down-wash. The biased spraying toward right side causes uneven spray pattern. In this study, a raised tail rotor system for the roll-balanced helicopter was studied. Thrust of the tail rotor system was measured and theoretically estimated for the fundamental database of the roll-balanced helicopter design. The estimated tail thrust and roll-moment would be used to design the raising height of tail rotor and roll balancing dynamics. The unmanned agricultural helicopter required the tail rotor thrust of about 39.2 N (4.0 kgf) during hovering with a payload of 235.4 N (24 kgf). A raised tail rotor system would compensate for the physical tilt phenomena. A further attitude control system of helicopter would assist roll-balanced aerial spray application.