The development and application of an electrical wheelchair with multiple-control (II)

重度殘障者在電動輪椅操控上或反應上遠不 及一般人，往往需要依靠看護或其他人的協助， 才能避免一些不必要的危險發生，如可以發展一 套具有安全回授系統之電動輪椅，將可以降低人 為操作的疏忽，讓老年人或重度殘障者擁有更加 獨立自主的行動力。 本系統利用感測器電路配合美國德州儀器公 司所生產的TMS320LF2407A 數位信號處理器控制 做為核心。此數位訊號負責辨識搖桿訊號能量大 小，來控制馬達轉向與速度。並佐以超音波及旋 轉編碼器加強輪椅的安全性。 為了達到整合輔具於同一介面上，故使用 M3S(Multiple Master Multiple slave)系統做為 本系統的運作核心，藉由此方式可降低系統之複 雜性，以提升此輪椅系統的安全性。The purpose of this study is to develop a safety feedback control system of a power wheelchair for the improvement of self-reliance in personal ambulation and the reduction of system errors due to operational faults. The core processor is a Texas Instrument TMS320LF2407A DSP (digital signal processor). The DSP reads the signal received from the joystick and carries out computations for the control of driving motors, both in direction and speed. An ultrasound module is used for the detection of obstacles in the rear side for safety. Optical encoders generate feedback signals in order to compensate the speed of the two motors by a PD control algorithm, which makes the speed of the power wheelchair independent of the weight load. This system is designed according to M3S (Multiple Master Multiple Slave) standards for a straightforward integration of additional modules and better expansion of a power wheelchair system