痙孿度限制下之伺服馬達時間最佳化控制

Abstract

本論文提出一種痙攣度(Snap)限制下之伺服馬達時間最佳化控制，以使伺服系統有平順的輸出響應。痙攣度，為位置的四階導數，又名Jounce，亦即分別為急動度(Jerk)、加速度與速度的一階、二階與三階導數。過大的痙攣度可能會對系統造成不良的影響，故本文提出一痙攣度限制下之時間最佳化伺服控制法(Snap-constrained time-optimal control, SCTOC)，其中包含位置控制與速度控制，此控制法不僅能限制最大痙攣度，又可達到最佳時間化的效果。SCTOC速度控制上是利用最佳時間控制器，結合一積分器與受控體串聯；在位置控制上則是利用最佳時間控制器結合兩積分器與受控體串聯;兩者皆直接地控制系統的痙攣度，因此可滿足最大痙攣度的限制。 由於提出的SCTOC是一種依賴受控體模型及俱備切換法則的控制法，因此容易受到系統不確定性及系統干擾的影響。故在系統中加入一積分型動態補償干擾估測器(dynamically compensated integral disturbance observer, DC-IDOB)以補償干擾降低其對系統的影響。 本文實驗受控體為無刷伺服馬達，以TI TMS320C6713 DSP與Xilinx 可程式閘陣列(FPGA)結合之單元為控制器，分別以C語言及硬體描述語言(VHDL)撰寫。以此平台為實驗系統，實現本文提出之痙攣度限制下之時間最佳化伺服控制法則，並由實驗結果證實其此控制法的可行及實用性。This paper presents a model-based time-optimal method under constraint on the maximum admissible snap. Snap, also known as jounce, is the fourth derivative of position, which is also the first, second and third derivatives of jerk, acceleration and velocity, respectively. Too large snap may have adverse effects on systems. Thus, snap-constrained time-optimal control method is proposed, including position and velocity control. This method not only limits the maximum snap but also has a time-optimal characteristic. The SCTOC for velocity control uses a time-optimal controller paired with an integrator that is in series with the plant. The SCTOC for position control uses a time-optimal controller paired with two integrators that are in series with the plant. Both SCTOCs directly control the system’s snap and thus are able to fulfill the snap constraint. This paper employs a symmetrically loaded servo motor as an experimental setup for the proposed control method. In the experimental system, the control kernel is a DSP/FPGA system, and the C language and VHDL are utilized as development tools for the servo control system. Experiments were conducted, and experimental results demonstrated that the SCTOC has better transient and steady responses than past approaches