Q2. What are the future works mentioned in the paper "A contribution to vision-based autonomous helicopter flight in urban environments" ?
This will be the objective of their future work.
Q3. What is the effect of pooling pixels by blocks of p p?
Pooling pixels by blocks of p × p multiplies the amplitude of detectable motions by p, and reduces the number of pixels considered by p × p.
Q4. What is the effect of the halteres on the optic flow?
if the housefly seems to be shortening its turning periods as much as possible, it nevertheless does not give up any control ability and uses the inertial information provided by its halteres to compensate for the rotational component of the optic flow.
Q5. What is the standard deviation of velocity in a cluttered environment?
The standard deviation of velocity is closely linked to the standard deviation of the mean obstacle distance: in cluttered environments, this value remains relatively constant and low, whereas, in less cluttered environments, it ranges from high values - when the robot is in an open space - to low values - when the robot reaches a corridor or approaches a wall.
Q6. What is the reason for the rotational component of the optic flow?
the rotational component of the optic flow does not depend on distance and, therefore, corrupts the measurement of the translational component.
Q7. What is the effect of the clutter response on bees?
Bees also exhibit a clutter response that allows their speed to be adapted to the width of the tunnel by maintaining a constant average motion [38].
Q8. What is the lateral velocity of the helicopter?
VxPx + ωy(1 + r 2 j ) − ωz(ri.rj) − ωx.ri (15)Because the low-level controller prevents the helicopter from skidding aside, the lateral velocity Vy can be set to zero.
Q9. What is the effect of the reactive navigation system on the housefly?
Beyond their flying manoeuvrability, they benefit from a reactive navigation system that enables them to wander in cluttered environments thanks to on-line monitoring of the optic flow.
Q10. How many experiments were performed in environment 3?
in order to estimate the robustness of their controller with respect to sensor errors, 5 series of 20 experiments using different noise levels were performed in environment 3 - the most cluttered.
Q11. What is the effect of introducing a low-pass filter on, righth?
Introducing a low-pass filter on η, M righth and M left h (see Fig. 2) makes the resulting strategy more efficient, even if it adds a delay in the control loop.
Q12. What is the effect of the low-level controller?
The experimental results described below demonstrate that this low-level controller provides a high close-loop bandwidth and affords efficient capacities for perturbation resistance.
Q13. What is the way to determine the motion of a pixel?
to determine this motion is computationally expensive and hardly applicable to real-time applications because of the quadratic dependency of the search upon n, the maximum motion detected.
Q14. What is the name of the simulated robot?
The simulated robot is a rotary-wing UAV inspired from the Concept 60 SR II (Fig. 1), a remote-controlled helicopter produced by Kyosho 3 .
Q15. How many times the noise level is beyond the nominal values?
It is only beyond unrealistic noise levels, attaining or exceeding three times the nominal values, that crashes cannot be avoided.
Q16. What is the relationship between the helicopter and the lateral velocity?
From Fig. 5, the following relationship may be derived:h Y = f X (2)As the low-level controller prevents the helicopter from skidding aside, the authors make the assumption than the lateral velocity Vy is null.