This paper proposes a technique to estimate the angular velocity of a rigid body from vector measurements. Compared to the approaches presented in the literature, it does not use attitude information nor rate gyros as inputs. Instead, vector measurements are directly filtered through a nonlinear observer estimating the angular velocity. Convergence is established using a detailed analysis of th...

A new estimator for determining the two-dimensional velocity vector using a pulsed ultrasound field is derived. The estimator uses a transversely modulated ultrasound field for probing the moving medium under investigation. A modified autocorrelation approach is used in the velocity estimation. The new estimator automatically compensates for the axial velocity when determining the transverse ve...

J = cost function N = number of impulses NLT = number of low-thrust-independent thrusters p = primer-vector magnitude p = primer vector pm = primer-vector absolute maximum r = relative position vector rj = space collocation of the jth impulse tf = final time tint = intermediate time tj = time instant of the jth impulse application tm = midcourse time corresponding to the primer absolute maximum...

It is a well-known limitation of all commercially available scanners that only the velocity component along the propagation direction of the emitted pulse is measured, when evaluating blood velocities with ultrasound. Proposals for solving this limitation using several transducers or speckle tracking can be found in the literature, but no method with a satisfactory performance has been found th...