scholarly journals Control of a biped robot by total rate of angular momentum using the task function approach

2005 ◽  
Vol 2 (2) ◽  
pp. 111-116
Author(s):  
J. A. Rojas-Estrada ◽  
J. Marot ◽  
P. Sardain ◽  
G. Bessonnet
Keyword(s):  
Angular Momentum ◽  
Biped Robot ◽  
Function Approach ◽  
Total Rate

scholarly journals Control of a Biped Robot by Total Rate of Angular Momentum Using the Task Function Approach

2005 ◽  
Vol 2 (2) ◽  
pp. 111-116
Author(s):  
J. A. Rojas-Estrada ◽  
J. Marot ◽  
P. Sardain ◽  
G. Bessonnet
Keyword(s):  
Angular Momentum ◽  
Control Problem ◽  
Degrees Of Freedom ◽  
Biped Robot ◽  
Function Approach ◽  
Control Law ◽  
Total Rate ◽  
Biped Robots ◽  
Formal Problem

In this work we address the control problem of biped robots by using the task function approach. A problem arrives when one of the feet is in contact with the ground, which presents imperfections. There is then the possibility that the biped robot undergoes a fall. It is difficult to track any trajectory due to the presence of unevenness on the ground. What we propose is to use the task function approach combined with the application of the total rate of angular momentum to obtain a control law for the ankle. By this technique, the tracking becomes more smooth and the balance is assured. The control law proposed allows the upper part of the robot to be controlled independently since only the ankle actuators are concerned. We enounce the formal problem and present some simulations with real parameters of a 21 degrees of freedom biped robot.

scholarly journals ENTROPY OF EXTREMAL WARPED BLACK HOLES

2009 ◽  
Vol 24 (19) ◽  
pp. 1485-1493 ◽  
Author(s):  
YUN SOO MYUNG
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Angular Momentum ◽  
Cosmological Constant ◽  
Massive Gravity ◽  
Entropy Function ◽  
Function Approach ◽  
Negative Cosmological Constant ◽  
Topologically Massive Gravity ◽  
Cardy Formula

We study the entropy of extremal warped black hole obtained from the topologically massive gravity with a negative cosmological constant of Λ = -1/l2. We compare the entropy Se = πα/3G from the Wald formalism with Sw = πl u /3G from the entropy function approach. These are the same if α = l u. Also we obtain the same Cardy formula when Je = l3 q with Je the angular momentum and q the conserved quantity.

scholarly journals Detectability of gravitational waves from a population of inspiralling black holes in Milky Way-mass galaxies

2021 ◽  
Vol 502 (3) ◽  
pp. 3932-3941
Author(s):  
Razieh Emami ◽  
Abraham Loeb
Keyword(s):  
Black Holes ◽  
Angular Momentum ◽  
Milky Way ◽  
Diffusion Rate ◽  
Signal To Noise Ratio ◽  
Space Distribution ◽  
Total Rate ◽  
Loss Cone ◽  
Replenishment Rate ◽  
The Impact

ABSTRACT We estimate the rate of inspiral for a population of stellar mass black holes in the star cluster around the supermassive black hole (SMBHs) at the centre of Milky Way mass galaxies. Our approach is based on an orbit averaged Fokker Planck approach. This is then followed by a post-processing approach, which incorporates the impact of the angular momentum diffusion and the GW dissipation in the evolution of system. We make a sample of 104 BHs with different initial semimajor and eccentricities with the distribution of fc(a)/a and e, respectively, where fc(a) refers to the phase–space distribution function for cth species. Angular momentum diffusion leads to an enhancement in the eccentricity of every system in the above sample and so increases the rate of inspiral. We compute the fraction of time that every system spends in the LISA band with the signal-to-noise ratio $\rm {S/N} \ge 8$. Every system eventually approaches the loss-cone with a replenishment rate given by the diffusion rate of the cluster, $\mu / \rm {Gyr}^{-1} \lesssim 1$. This small rate reduces the total rate of the inspiral for individual MW mass galaxies with an estimate Robs ≲ 10−6−10−5 yr−1. A large collection of galaxies (Ngal > 104 MW) may lead to an observable GW signal in the LISA band.

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