Coreless DC Motor Drive System Design by Variable Structure Scheme

Although coreless motors have simple linear dynamic models with low complexity level regarding to the control of usual applications, frequently some kind of noise or vibration may arise if the coreless motor is operated in a general high gain control which is easy to deteriorate the performance. Besides, for most of the drive systems, the inner-loop current controllers are usually designed to be realized by proportional plus integral (PI) controller with its easily adjustable parameters. However, systems controlled by PI scheme are weak in robustness, and their performances are easily affected by disturbances and loads, or other situations such as nonlinearity. As regards to the variable structure control (VSC), it is known that systems controlled by VSC have the properties of fast response and robustness. And in drive system design, the VSC is usually designed for the outer loop velocity/position control, and chattering phenomenon must be solved. In this study, we apply VSC to the coreless DC motor drive for current loop control to get a fast response. The controller is realized by TI TMS320F28069 DSP. The experimental results of VSC-based system are compared with the system controlled by PI controller to verify the validation of the proposed drive scheme.