A novel angle measurement method for V-port ball valve based on millimeter-wave radar

Abstract This paper presents an innovative method for measuring the rotation angle of a V-port ball valve core using millimeter-wave (MMW) radar. It exploits variations in echo signal amplitude that arise from differences in reflector orientation and target size. First, as the valve core rotates, its reflective area changes and the radar echo signal amplitude varies accordingly. Then, the MMW radar unit continuously captures these signals throughout the rotation process. The signals undergo adaptive complementary ensemble empirical mode decomposition and are subsequently reconstructed. The process of parameter optimization further enhances the accuracy of this decomposition. After that, a mathematical model relates the reconstructed characteristics of the signals directly to the valve core angles, thereby enabling precise quantification of the opening degrees. Experimental trials demonstrate that this radar-based approach delivers rotation-angle measurements with a maximum relative deviation below 0.25%, compared to the performance of an angle encoder. Moreover, the proposed method operates without mechanical coupling, occupies minimal space and installs easily on an existing valve assembly. The novel method establishes the technique as a viable solution for the control of industrial valves.