Nonlinear estimation-based dipole source localization for artificial lateral line systems

Abstract

As a flow-sensing organ, the lateral line system plays an important role in various behaviors of fish. An engineering equivalent of a biological lateral line is of great interest to the navigation and control of underwater robots and vehicles. A vibrating sphere, also known as a dipole source, can emulate the rhythmic movement of fins and body appendages, and has been widely used as a stimulus in the study of biological lateral lines. Dipole source localization has also become a benchmark problem in the development of artificial lateral lines. In this paper we present two novel iterative schemes, referred to as Gauss-Newton (GN) and Newton-Raphson (NR) algorithms, for simultaneously localizing a dipole source and estimating its vibration amplitude and orientation, based on the analytical model for a dipole-generated flow field. The performance of the GN and NR methods is first confirmed with simulation results and the Cramer-Rao bound (CRB) analysis. Experiments are further conducted on an artificial lateral line prototype, consisting of six millimeter-scale ionic polymer-metal composite sensors with intra-sensor spacing optimized with CRB analysis. Consistent with simulation results, the experimental results show that both GN and NR schemes are able to simultaneously estimate the source location, vibration amplitude and orientation with comparable precision. Specifically, the maximum localization error is less than 5% of the body length (BL) when the source is within the distance of one BL. Experimental results have also shown that the proposed schemes are superior to the beamforming method, one of the most competitive approaches reported in literature, in terms of accuracy and computational efficiency.

A Review of Artificial Lateral Line in Sensor Fabrication and Bionic Applications for Robot Fish

“…Abdulsadda et al [18, 35, 50–52] exploited the inherent sensing capability of ionic polymer-metal composites (IPMCs) to develop ALL sensors (Figure 5(c)). The composites consisted of three layers and an ion-exchange polymer membrane placed between the metal electrodes.…”

Micro-Machined Flow Sensors Mimicking Lateral Line Canal Neuromasts

“…The capacitive detection principle was also used to fabricate bioinspired sensors based on fish SNs that contained an SU-8 hair cell [46,62]. Some flow sensors are based on the piezo-electric or depolarization detection principle [47,[63][64][65][66]. These hair cell-inspired sensors were made from ionic polymer-metal composites (IPMCs).…”

Speed evaluation of a freely swimming robotic fish with an artificial lateral line

“…Therefore, from the first artificial lateral line system was developed [4], artificial lateral line research has been drawing more and more attentions in recent years. Some of the reported major studies in the literature include dipole source localization [5], [6], local analysis of the surrounding steady and unsteady flows [7], closed-loop control of an underwater robot [8], [9], and flow features extraction while considering selfmotion effects of the robot [10], [11]. These studies have progressively advanced the understanding of hydrodynamic signatures by extracting meaningful information from the flow sensor readings.…”