Discrete trajectory control algorithms for NIMS3D, an autonomous underconstrained three-dimensional cabled robot

Abstract

Abstract-In this paper we present algorithms that enable precise trajectory control of NIMS3D, an underconstrained, three-dimensional cabled robot intended for use in actuated sensing. We begin by offering a brief system overview and then describe methods to determine the range of operation of the robot. Next, a discrete-time model of the system is presented. Thereafter, we present an online algorithm for modeling motor behavior. The majority of the paper is dedicated to describing three feedback control laws used to enable accurate trajectory tracking for both linear and non-linear motion profiles. We present experimental results that highlight the strengths and weaknesses of these mechanisms and conclude by offering a series of future plans for NIMS3D.

Forest understory soil temperatures and heat flux calculated using a Fourier model and scaled using a digital camera

“…Several studies have incorporated mobility with environmental sensing, decreasing sensing uncertainty and increasing the physical range of sensing (Caron et al, 2008;Graham et al, 2009) or time of sampling (Singh et al, 2007). Innovation in movement of sensors in three dimensions promises even greater sensing capabilities (Borgstrom et al, 2007). In this study, mobility of sensors along a linear transect allowed us to measure soil surface temperature at a high spatial resolution over the course of multiple days while simultaneously sampling with fixed sensors.…”

Mathematical model of the aerial robotic camera base on its geometric relationship

“…The desired motion trajectory of the camera is defined in x, y, z Cartesian coordinates, and it is generated by motion of three motors 1  , 2  , 3  . The kinematic model of the CPR-C system has been developed as essential part for solving the CPR-C system dynamics.…”

“…1. The relation between the camera motion in the Cartesian space x, y, z and angular positions of each motor 1  , 2  , 3  is solved by the Jacobian matrix c J , which connects velocities of external coordinates changes [ ]…”

“…In paper [3] authors present algorithms that enable precise trajectory control of NIMS3D, an under constrained, three-dimensional cabled robot intended for use in actuated sensing. They begin by offering a brief system overview and then describe methods to determine the range of operation of the robot.…”

Cable-suspended CPR-D type parallel robot

“…The workspace conditions and the dynamics of the manipulator were described in details. Borgstrom et al (2007) presented algorithms that enabled precise trajectory control of the Networked Info Mechanical Systems (NIMS), and under constrained three-dimensional (3D) cabled robot intended for use in actuated sensing. Several prototypes of the wire-driven parallel robots with different actuation schemes were presented by Merlet (2010).…”