Technologies and applications of angle sensors: a review

This paper presents a critical review of advancements made in the area of non-contact angle sensing in the last two decades. Angular position sensing is an essential function in most of the engineering systems associated with industries such as automotive, robotics, process, and aircraft. The review shows significant progress that has been achieved in the performance aspects of angle sensors, overcoming the challenges introduced by new and specific applications. Progress is also visible in effectively utilizing the emerging allied technologies on the sensing and electronics field for the development of high-end angle sensors. As a part of the review, the important sensing techniques utilized for the angle sensors are identified and carefully looked at the advantages and limitations of those. Besides, the potential areas for improvements are also suggested. The important techniques employed to design and develop the angle sensors are based on capacitive, inductive, magneto-resistive, and optical schemes. Signal conditioning circuits, analog or digital, or a combination of it, are necessary to derive the best from the sensing elements. They play a vital role in the overall performance of the sensor. The review addresses the advancement in the sensing element, methodology, and signal conditioning aspect in detail. In this review, the important angle sensors reported are evaluated against the performance parameters such as range, resolution, linearity, accuracy, sensitivity, power consumption, complexity, cost, manufacturability, and reliability.