本論文的主要目的是探討使盲用點字印表機中的打點器之週期時間為最小之控制的方法。傳統的方法是在打點器上加一個夠長的電壓脈衝，使撞針能夠撞擊到紙面。但為了確保能夠真正撞擊到紙面，通常此脈衝電壓的時間都相當長，導致整個週期時間過長。本論文首先提出一種利用電流的變化來估測打點器的撞針是否已經撞擊到紙面的方法，藉由此種方法來控制電壓命令的關閉，使得打點字的時間可以縮短。接著探討一利用電能與機械能守恆的原理以更進一步縮短點字時間，使點字週期時間最小化之控制方法。論文除了理論分析此控制法則外，並藉由模擬與實驗的結果來驗證提出的理論。 This paper describes two control schemes that can be applied to reduceprinting time of the Braille printer. The first scheme involvesdetection of the instance at which the plunger hit the paper using themeasured coil current. With this scheme, the voltage driving thesolenoid actuator can be turned off immediately after the plunger hitthe paper, therefore reduce the printing time. However, the firstscheme does not yield a minimum printing time since the plunger forceis much larger than the dragging force exerted by the spring attachedat the plunger at the instant of hit. Therefore another scheme thatcan yield a minimum printing time is proposed, the scheme is deducedbased on the energy balance at the instance of hit. Both simulationand experimental are performed to verify the proposed control schemes.
