A conceptual high-resolution MR encoder and torque transducer for precision actuators

This dissertation analytically and experimentally demonstrated a conceptual solution for the high-resolution position sensing, and torque sensing requirements of precision, intelligent machines. The method included an evaluation of the advanced actuators non-linearities and parametric coupling. An analysis of current industrial and research-level sensing practices in robots will be conducted. The purpose of this analysis established the degree to which current practices adequately address the precision requirements of advanced machines. Subsequently, based on this need and relevance, an investigation and analysis of the primary actuator level sensors was conducted. The physics and technologies were identified and measured relative each other and the actuator requirements. A select down of the technologies was conducted.; The magnetoresistive phenomenon was investigated in-depth. The performance of the magnetic recording channel has been analyzed relative to the rotary encoder requirements of the advanced actuator. Based on this investigation, through the application of a set of governing design equations, a MR encoder model has been developed. This model includes system non-linearities and noise sources. Both the MR encoder and MR torque sensor conceptual designs have been presented. Limitations in current technology have been identified and proposed alternatives proposed. Finally, the MR encoder concept has been simulated. An experimental test-bed has been developed to collect actual MR read head signals and incorporated into the model. The data has been summarized and the future research identified.