Inertia

About: Inertia is a research topic. Over the lifetime, 12006 publications have been published within this topic receiving 164291 citations.

On-Orbit Identification of Inertia Properties of Spacecraft Using a Robotic Arm

Abstract: This paper presents a robotics-based method for on-orbit identification of inertia properties of spacecraft. The method makes use of an onboard robotic arm to change the inertia distribution of the spacecraft system. As a result of the inertia redistribution, the velocity of the spacecraft system will change correspondingly. Because the velocity change is measurable and the inertia redistribution of the robotic arm itself is precisely computable, the inertia parameters of the spacecraft body become the only unknown in the momentum equations and, hence, can be identified from the momentum equations of the spacecraft system. To treat the problem as a linear identification problem, it has to be solved in two steps. The first step is to identify the mass and mass center of the spacecraft; and the second step is to identify the inertia tensor of the spacecraft. The advantages of this method are 1) it does not consume fuel because a robotic subsystem is energized by solar power; 2) it requires measuring velocities only, but not accelerations and forces; and 3) it is not affected by internal forces, which are difficult to accurately measure. The paper investigates the sensitivity of the method with respect to different arm/spacecraft mass ratios, arm motion trajectories, and velocity-measurement errors.

Structural Inertia and Organizational Change Revisited III: The Evolution of Organizational Inertia

Abstract: Building on a formal theory of the structural aspects of organizational change initiated in Hannan, Polos, and Carroll (2002a, 2002b), this paper focuses on structural inertia We define inertia as a persistent organizational resistance to changing architectural features We examine the evolutionary consequences of architectural inertia The main theorem holds that selection favors architectural inertia in the sense that the median level of inertia in cohort of organizations presumably increases over time A second theorem holds that the selection intensity favoring architectural inertia is greater when foresight about the consequences of changes is more limited According to the prior theory of Hannan, Polos, and Carroll (2002a, 2002b), foresight is limited by complexity and opacity Thus it follows that the selection intensity favoring architectural inertia is stronger in populations composed of complex and opaque organizations that in those composed of simple and transparent ones

Virtual Inertia Control Strategy in Microgrid Based on Virtual Synchronous Generator Technology

Abstract: Although the virtual inertia algorithm can be used to enhance the inertia of microgrid system, the strong coupling and low precision always limit its popularization and application. Therefore, a novel virtual inertia control strategy is proposed in this paper. Combining with the potential inertia advantages of virtual synchronous generator (VSG) technology, the poor compatibility between the virtual inertia principle and the energy storage control algorithm is analyzed in detail. In order to improve the control precision, this paper focuses on the analysis of frequency response characteristics of alternating current (ac) side and then regulates the ac frequency more directly and accurately by the virtual inertia generated from the energy storage device and the grid-connected inverter. Thus, additional droop characteristic, particular control algorithm of energy storage device, and power given module are designed, respectively, to make the system provide virtual inertia power support actively under multi disturbance operation. The novel virtual inertia control strategy can effectively deal with all kinds of wind speed and ac load mutation and restrain the frequency variation on ac side. Finally, the correctness and feasibility of the proposed scheme are verified by the simulation results.

Game Physics Engine Development

Abstract: 1. Introduction I Particle Physics 2. The Mathematics of Particles 3. The Laws of Motion 4. The Particle Physics Engine II Mass Aggregate Physics 5. Adding General Forces 6. Springs and Spring-like Things 7. Hard Constraints 8. The Mass Aggregate Physics Engine III Rigid Body Physics 9. The Mathematics of Rotations 10. Laws of Motion for Rigid Bodies 11. The Rigid Body Physics Engine IV Collision Detection 12. Collision Detection 13. Generating Contacts V Contact Physics 14. Collision Resolution 15. Resting Contacts and Friction 16. Stability and Optimization 17. Putting It All Together VI Horizons 18. Other Types of Physics 19. A Physics Based Game A. Mathematics Summary B. Common Inertia Tensors C. Other Programming Languages D. References

Inertia-Controlled Ambipolar Diffusion

Abstract: The general nonlinear ambipolar‐flow equations are derived and discussed. The important non‐linearities are caused by the inertia of the ions and by the heat‐conduction mechanism. It is shown that all essential effects associated with these nonlinearities can be demonstrated in the plane‐parallel case. The influence of the nonlinearity caused by the inertia is discussed in detail for the plane‐parallel case and it is shown that this flow is analogous to the flow of a fluid with friction through a contracting nozzle. The limiting velocity—the isothermal or the adiabatic sound velocity—which is found in the exit of a nozzle is also found at the boundary in the case of inertia‐controlled diffusion, provided this boundary acts like a perfect sink. Bohm's criterion—the ion drift velocity less than or equal to the sound velocity of the electron‐ion gas in front of the boundary or the wall sheath—appears as an integral part of the inertia‐controlled‐diffusion theory. In the inertia‐controlled‐diffusion theory are incorporated, as integral parts, all the assumptions that necessarily must be added to the linear‐diffusion theory in order to make it realistic. The isothermal and inertia‐controlled diffusion leads always to wall‐stabilized plasma configurations which directly correspond to the fundamental mode solution in the linear‐diffusion theory.