No. 3 - Manuel Haide

Manuel Haide: Durchflussmessung mit Ultraschall-Phased-Array-Sensoren

External publication 2016

Commission

• Prof. Dr.-Ing. Gerhard Schmidt
  (first reviewer)
• Prof. Dr.-Ing. Wolfgang Schroer
  (second reviewer)
• Prof. Dr.-Ing. habil. Thomas Meurer
  (examiner)
• Prof. Dr.-Ing. Werner Rosenkranz
  (head of the examination board)

Abstract

Future development of reliable flow measurement in urban water management, flood control, process and power engineering are driven by developing wear-free and flexible measurement systems with high accuracy. Current ultrasonic measurement systems are limited in their scope and thus signal processing and sensor design need to be improved. The basis of the discussed measuring principle are sound-reflecting suspended solids in the fluid, which move slip-free along the stream.

This thesis presents fused signal processing methods to determine velocities of suspended solids in fluids. In combination with a phased-array ultrasonic sensor, a successive measurement of the velocity prole across the entire channel or pipe cross section can be performed. Moreover, signals are transmitted with a frequency hopping coding in order to detect a position-dependent information of the transit time and Doppler frequency. With the objective of noise-resistant and accurate flow measurement, object tracking theories or cluster methods are used to fuse the received echo information.

The object tracking is realized by a Kalman lter and various local and global association methods such as the Neares-Neighbour- and (Joint) Probabilistic Data Associations method. In contrast to this time-based tracking of streamlines, the cluster method determines the Doppler frequency by an application-oriented MUSIC method. Areas which are beyond of the phased-array sensor coverage, are complemented by a computational optimized function to generate a velocity distribution across the entire channel / pipe cross section. The technical feasibility of the analyzed evaluation methods as well as the sensor system has been adduced by a hardware platform.

By using the data fusion methods measurement errors have been reduced for high in flow velocities. Ambiguities in the Doppler frequency interpretation are cancelled by the data fusion, and thus enlarge the measurement range. In combination with the ultrasonic phased-array technology inhomogeneous velocity proles are determined across the entire channel / pipe cross section.