| 摘要 |
A wheelchair having a seat and a plurality of wheels for rolling the wheelchair along a ground surface. A plurality of legs are provided for supporting the seat. Each of the legs is positioned between the seat and one of the wheels. A plurality of struts are also provided. Each of the struts couples a first of the legs to a second of the legs. Each of the legs bears only compressive force in supporting the seat, and each of the struts bears only tensile force. A foldable wheelchair formed from a seat bottom and a seat back pivotally coupled to the seat bottom. The seat back is movable between a folded position and an unfolded position. The seat bottom has a back end formed from a first curved shape, and the seat back has a bottom end formed from a second curved shape. The first curved shape of the seat bottom is sized to mate with the second curved shape of the seat back when the seat back is in the unfolded position. A portable mobility device that includes an actuator for providing at least one actuator output signal in response to movement of the actuator by a user of the device. The actuator is movable over a range of positions, the range of positions being bounded by a minimum speed actuator position at a first end of the range and a maximum speed actuator position at an opposite end of the range. The range of positions includes a mid-point actuator position located on the range exactly midway between the minimum speed actuator position and the maximum speed actuator position. The actuator output signal has a magnitude that is linearly related to the position of the actuator on the range of positions. A nonlinear amplifier, responsive to the actuator output signal, is provided for outputting a motor control signal. The motor control signal has a minimum value when the actuator is located at the minimum speed actuator position, a maximum value when the actuator is located at the maximum speed actuator position, and the motor control signal has its median value when the actuator is located between the mid-point speed actuator position and the maximum speed actuator position.
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