This article concerns the stability analysis of a control system for dynamic body weight support in rehabilitation device re-education human gait. The paper presents physical model device, which characterizes most important phenomena associated with movement system, i.e., inertia, damping, and elasticity. has one active passive element. They are connected by connector elastic damping properties...

We have recently proved that a two relay controller produces oscillations at the scalar output of an underactuated system where the desired amplitude and frequency are reached by choosing its gains but being too sensitive to disturbances. In this paper we go much further and develop a reference model, based on two-relay controller, to generate a set of desired trajectories for the inertia wheel...

This article presents the first swing-stabilization control for indoor miniature autonomous blimps (MABs). Indoor MABs are safe to operate in close proximities humans and can fly multiple hours, but swing oscillation is commonly observed due their underactuated design unique aerodynamic shape. In this article, we analyze flight characteristics of MABs, describe swing-reducing system detail. Key...

In this paper, we obtain feedback laws to asymptotically stabilize relative equilibria of mechanical systems with symmetry. We use a notion of stability ‘modulo the group action’ developed by Patrick [1992]. We deal with both internal instability and with instability of the rigid motion. The methodology is that of potential shaping, but the system is allowed to be internally underactuated, i.e....

This paper discusses the problem of obtaining feedback laws to asymptotically stabilize relative equilibria of mechanical systems with symmetry. We show how to stabilize an internally unstable relative equilibrium using internal actuators. The methodology is that of potential shaping, but the system is allowed to be underactuated, i.e., have fewer actuators than the dimension of the shape space...

A new digital control method for a time varying sampled data system called a variable period deadbeat control is proposed to control high order nonholonomic chained systems with drift terms. This control law has a potential to avoid an excessive overshoot to prevent the trajectories close to the singular manifold of the transformation needed to obtain the chained forms. The control will be appl...

Effective design of autopilots for fixed-wing unmanned aerial vehicles (UAVs) is still a great challenge, due to unmodeled effects and uncertainties that these exhibit during flight. Unmodeled comprise longitudinal/lateral cross-couplings, as well poor knowledge equilibrium points (trimming points) the UAV dynamics. The main contribution this article new adaptive autopilot design, based on unce...

An adaptive neural network command-filtered backstepping design algorithm is proposed for the underactuated translational oscillator with a rotating actuator (TORA). The system dynamics are transformed into nonlinear cascade through global change of coordinates. Considering weak sinusoid-type interaction and affine-free appearance in model, TORA looked at as pure feedback system. Two networks u...