嵌入式即時運動控制核心為基礎之加速度回授控制器開發

The Development of Acceleration Feedback Controller based on Embedded Multitasking Real-Time Kernel

李峰吉(Feng-Ghi Li)

指導教授 ： 陳金聖

國立臺北科技大學/機電學院/自動化科技研究所/碩士(2006年)

https://doi.org/10.6841/NTUT.2006.00323

摘要

本文主要目的為開發一嵌入式即時多工運動控制器。採用德州儀器公司TMS320C6711 DSP與Xilinx公司 Spartan-II XC2S50 FPGA，分別規劃成嵌入式系統之運算核心與處理外部I/O之橋接界面，另外為了使軟體也能配合硬體之硬即時要求，也完成在DSP上嵌入一即時多工作業系統 ；以此為架構之嵌入式系統擁有許多優點，如透過作業系統的資源管理、使得資源能更有效運用；工作內容之模組化，使得軟體設計彈性且除錯也較為容易等。最後，充分利用所建構之即時多工平台，將運動控制核心之內容，拆解成數個工作模組實現於平台上，達成本文運動控制器實現目的。
在控制器設計主要採用Cascade控制器架構來完成，乃利用內迴路控制器高頻寬之設計，以阻斷干擾因子對外迴路受控變數之影響；本文內回路為加速度回授控制，在外回路為位置回授控制。內回路採加速回授控制，主要是希望加速度回授控制，以取代一般伺服控制器之電流回路控制。並且希望內回路干擾影響盡可能降低，故在加速度內回路設計干擾補償器，將干擾影響消除，使得外部位置回路不受干擾影響，提高系統之精度。
最後，成功的使用運算速度快與多樣I/O功能的數位訊號處理器，搭配 即時多工作業系統，完成嵌入式即時多工運動控制器開發，透過實驗驗證，本嵌入式系統穩定性佳並具即時性，達到運動控制器高速與高精度之目標。

關鍵字

關鍵詞：硬即時 ； 即時多工核心 ； 電腦數值運動控制器 ； 加速度回授控制 ； 干擾補償器

並列摘要

Industrial motion controller is usually developed in two phases: motion control design and real-time implementation. For first phase, this thesis presents a digital servo driver that realizes a novel feedback controller based on position, velocity and acceleration feedback using optical encoder information. Compared with the conventional cascade control system, this novel control scheme has high bandwidth and robustness. For second phase, this thesis develops an embedded motion controller based on TI TMS320C6711 DSP, XILINX Spartan-II XC2S50 FPGA and multitasking real-time kernel.
Acceleration feedback can improve the performance of motion control in motor drives. Acceleration control is, however, seldom implemented in practical drive systems due to the unsatisfactory results of most acceleration measurement methods. A digital state observer is firstly proposed to estimate the velocity and acceleration of DC motor in this paper. Then, we design a model-based disturbance compensator (MBDC) in the acceleration feedback loop to compensate the influence of disturbance. When the DC servo motor is controlled by the proposed acceleration feedback control system, the total servo system from acceleration to position becomes the acceleration controlled system which is fixed to a nominal double integral dynamics in the presence of parameter variation and torque disturbance. Hence, the fast and precise position control can be carried out easily.
In this paper, the control scheme is implemented based on the TI TMS320C6711 DSP and XILINX Spartan-II XC2S50 FPGA. The DSP take the main task of control firmware and FPGA take the tasks of communication handshake and interface to DC motor amplifier. The proposed acceleration feedback controller and PD position feedback controller are evaluated on the DSP, which is ported a multi-tasking real-time operation system (RTOS), controlled DC servo motor positioning system. The experimental results show that this digital servo system is flexibility, robustness and remarkably reduces the tracking error.

並列關鍵字

Keywords：Hard real-time ； Multi-tasking real-time operation system ； Computerized numerical controller ； Acceleration feedback control ； Model-based disturbance compensator.

參考文獻

[25] 陳立業，“即時NURBS多維運動軌跡精度補償策略”，台北科技大學自動化科技研究所，碩士論文，民國九十四年。

[1] George Ellis and Jens Ohno Krah, Observer-based Resolver Conversion in Industrial Servo System.

[2] Peter B. Schmidt and Robert D. Lorenz, Design Principle and Implementation of Acceleration Feedback to Improve Performance of dc Driver, IEEE Transactions on Iindustry Aapplication, vol.28, NO.3, 1992.

[3] Sami Valiviita and Seppo J. Ovaska, Delayless Acceleration Measurement Method for Elevator Control, IEEE Transactions on Industry Application, vol.45, NO.2, 1998.

[4] Pierre R. Belanger, Estimation of Angular Velocity and Acceleration from Shaft Encoder Measurements, IEEE International Conference on Robotics and Automation, 1992.