Path Generation for High-Performance Motion of ROVs Based on a Reference Model

Abstract

This paper deals with the generation of sufficiently smooth position, velocity, and acceleration references for guiding the motion of an ROV along purposefully defined curvature-continuous paths in automated missions. The references are meant to be employed in high-performance trajectory tracking and dynamic positioning applications. The path planning problem is not in the scope of this work. A reference model that synthesises references concerning a single Degree-of-Freedom (DoF) motion is initially described. Then, the use of the synthesised references as the parametrisation for other references concerning multiple DoF motion along curvature-continuous paths is exploited. Results from computer simulations and full-scale sea trials, both based on the NTNU's ROV Minerva, are presented and discussed.Keywords: Guidance system, Path generation, Reference model, ROV, Trajectory tracking. List of acronyms and abbreviations

Path planning with Pythagorean-hodograph curves for unmanned or autonomous vehicles

“…This amounts to a translation/rotation/scaling transformation, that maps q 0 and q 1 to the points 0 and 1 on the real axis. Once the canonical form solution has been computed, it can be restored to the original coordinates by taking p 0 ¼ q 0 in (5) and multiplying w 0 , w 1 , w 2 by ffiffiffiffiffiffiffiffiffi jÁqj p exp i 1 2 À Á before substituting in (5). For brevity, only the generic case 1 6 ¼ AE 0 is considered here.…”

“…Many authors have recently proposed the use of Pythagorean-hodograph (PH) curves in the context of path planning for autonomous or remotely operated aerial, land, or submarine vehicles, such as unmanned aerial vehicles (UAVs) or autonomous underwater vehicles (AUVs). [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Feasible paths must satisfy various constraints, such as bounds on the path curvature or climb angle, avoidance of environmental obstacles, and maintenance of safe separations in vehicle swarms.…”

Geração de rotas planares com curvaturas contínuas a partir de rotas geradas pelo método dos campos potenciais artificiais

“…Rotas com curvaturas descontínuas podem causar uma série de problemasà locomoção de robôs e veículos, como acelerações abruptas, redução da segurança e do conforto de passageiros e animais transportados e até instabilidade de seus sistemas de controle; podem também elevar desnecessariamente o consumo de energia (Elbanhawi et al, 2015;Fernandes et al, 2015;Lau et al, 2009).…”

Helical polynomial curves interpolating G 1 data with prescribed axes and pitch angles

“…compute the control points (5) of p(ξ), and coefficients of its parametric speed and arc length σ(ξ) and s(ξ) from equations (6) and (7); 5. define the "lifted" helical path r(ξ) in terms of p(ξ) = (x(ξ), y(ξ)) and s(ξ) by equation (15), and obtain its control points from equation (20); 6. compute the coefficients of the quaternion polynomial (22) defined by (25) and ( From these values, the control points (20) of the "lifted" helical path may be computed using (5), (6), and (7).…”

“…There has recently been considerable interest in using Pythagorean-hodograph (PH) curves to specify paths for swarms of unmanned aerial vehicles (UAVs) or other autonomous or remotely-operated vehicles [1,3,4,6,20,21,23,24,25,26,27,28,29,30,31,33]. A polynomial PH curve r(ξ) = (x(ξ), y(ξ), z(ξ)) incorporates a special algebraic structure [9], ensuring that the components of the hodograph (derivative) r ′ (ξ) = (x ′ (ξ), y ′ (ξ), z ′ (ξ)) satisfy a Pythagorean condition -i.e., x ′2 (ξ)+y ′2 (ξ)+z ′2 (ξ) is equal to the perfect square of a single polynomial.…”