Improving in surface quality of precision thin-walled pipes

The causes for the occurrence of axial forces during the cold periodic rolling in the deformation zone are considered. Original method for solving of the axial forces minimization to increase the productivity of mills and the quality of the finished product is presented.

Rolling Locomotion Control of a Biologically Inspired Quadruped Robot Based on Energy Compensation

We have developed a biologically inspired reconfigurable quadruped robot which can perform walking and rolling locomotion and transform between walking and rolling by reconfiguring its legs. This paper presents an approach to control rolling locomotion with the biologically inspired quadruped robot. For controlling rolling locomotion, a controller which can compensate robot’s energy loss during rolling locomotion is designed based on a dynamic model of the quadruped robot. The dynamic model describes planar rolling locomotion based on an assumption that the quadruped robot does not fall down while rolling and the influences of collision and contact with the ground, and it is applied for computing the mechanical energy and a plant in a numerical simulation. The numerical simulation of rolling locomotion on the flat ground verifies the effectiveness of the proposed controller. The simulation results show that the quadruped robot can perform periodic rolling locomotion with the proposed energy-based controller. In conclusion, it is shown that the proposed control approach is effective in achieving the periodic rolling locomotion on the flat ground.

Analysis of Apparent Spontaneous Yawing for a Ship Under Way

In this paper a mathematical model is presented to explain the phenomenon of yawing oscillations of a ship, when sailing in a mean straight course with a constant mean speed. With this model, periodic yawing can be simulated as a result of simultaneous periodic rolling and pitching, emphatically without the input of any rudder action. Additionally, the study throws a new light on the old question of whether the Cardan suspension of the compass bowl should be with the outer gimbal axes fore and aft or athwartships.