This paper focuses on three commonly used sensorless methods based on high-frequency signal injection; namely, the rotating sinusoidal injection in the stationary reference frame, the pulsating sinusoidal injection in the estimated synchronous reference frame, and the pulsating square wave injection in the estimated synchronous reference frame. Although these methods have found applications in ...

In this paper, we tackle the problem of trajectory tracking for a particular class of underactuated vehicles with full torque actuation and a single force direction (thrust), which is fixed relative to a body attached frame. Additionally, we consider that thrust reversal is not available. Under some given assumptions, the control law that we propose is able to track a smooth reference position ...

We obtained new periodic solutions in the problems of three and four point vortices moving on a plane. In the case of three vortices, the system is reduced to a Hamiltonian system with one degree of freedom, and it is integrable. In the case of four vortices, the order is reduced to two degrees of freedom, and the system is not integrable. We present relative and absolute choreographies of thre...

In 3 experiments, the authors investigated spatial updating in augmented reality environments. Participants learned locations of virtual objects on the physical floor. They were turned to appropriate facing directions while blindfolded before making pointing judgments (e.g., "Imagine you are facing X. Point to Y"). Experiments manipulated the angular difference between the learning heading and ...

Original scientific paper A formulation for the kinematics of multibody systems is presented, which uses Lie group concepts. With line coordinates the kinematics is parameterized in terms of the screw coordinates of the joints. Thereupon, the Lagrangian motion equations are derived, and explicit expressions are given for the objects therein. It is shown how the kinematics and thus the motion eq...

It is argued that a ‘scene corpus’ would be a useful tool for the training and testing of systems for grounded spatial communication in the same way that text corpora have been used for training and assessing other language processing systems. Such a scene corpus would need to allow a full range of spatial relationships to be expressed over a range of scale spaces. The scenes should be sufficie...

1. We recorded from cells with sensory responses to somatosensory stimuli in the superior colliculus (SC) of awake monkeys. Our goal was to determine the frame of reference of collicular somatosensory signals by seeing whether the positions of the eyes influenced the responses of cells to a given tactile stimulus. Somatosensory targets consisted of vibrotactile stimuli delivered to the hands, w...

We construct solutions for the Navier-Stokes equations in three dimensions with a time periodic force which is of compact support in a frame that moves at constant speed. These solutions are related to solutions of the problem of a body which moves within an incompressible fluid at constant speed and rotates around an axis which is aligned with the motion. In contrast to other authors who anala...