A practical approach focused on optimal velocity profiles selection for hybrid stepper motors to maximize available synchronous torque utilization and minimize positioning error in open loop operation, with application to Manufacturing Systems.

Abstract In this article, the optimization of hybrid stepper motors performance in open loop is approached by movement strategy definition, adjusted to the load dynamics enabling the execution of movements using maximum synchronous torque available and with the minimum positioning error or step loss. A concept known as the equivalent power circuit time constant is proposed. This concept allowed the development of a practical approach to calculate the synchronous Pull-Out torque curves in terms of power control circuit characteristics and stepper motors electrical parameters. By combining this approach with the load characteristics in a dimensionless form, a differential equation is obtained whose solution provides the optimal stepping rate profile and the limits for the kinematic parameters such as maximum speed and minimum acceleration time allowed for synchronous movement. The proposal is validated through experimentation and obtained a low positioning error for exponential profiles compared to other widely used shapes of acceleration. During the project development, a test bench for the drive systems was designed and built. In addition, a case study is presented to show proposed methodology implementation.