L. Ródenas

Improving attitude estimation using inertial sensors for quadrotor control systems

Attitude estimation for an aerial vehicle using the Kalman Filter - KF- with experimental validation is presented in this paper. The data fusion is made using simplified representations of the kinematics of the aerial vehicle and the accelerometer measurement model. The resulting algorithm is computationally efficient as it can be run at up to 500 Hz on a low-cost microcontroller. The observer is improved by choosing the appropriate covariance and noise matrices. Numerical and in-flight validation are carried out using an experimental platform and a quadrotor prototype. The experimental results are compared online with the measurements coming from a commercial IMU -Inertial Measurement Unit.

Effect of Different Physical form Alfalfa on Methane Production in Murciano-Granadina Dairy Goats

Abstract López, M.C., Ródenas, L., Piquer, O., Martínez, E., Cerisuelo, A., Pascual, J.J. and Fernandez, C. 2010. Effect of different physical form alfalfa on methane production in Murciano-Granadina dairy goats. J. Appl. Anim. Res., 38: 93–96. To study the effect of physical form of alfalfa on methane production, long (L) or chopped (C) alfalfa hay was fed with barley (B) or corn (C) to three 2 years old Murciano-Granadina dairy goats. Sunflower meal (pelleted) was the main protein source for all diets. Chopping improved CP digestibility with either grain and fibre digestibility with corn only. Significant differences in methane production were observed for the effect of corn vs. barley, only for diets containing long alfalfa hay. Least methane was found for long alfalfa hay in combination with barley grain. Moderate lower methane production was found for chopped alfalfa without effect between corn vs. barley.

Different resource allocation strategies result from selection for litter size at weaning in rabbit does.

This study examined the effect of long-term selection of a maternal rabbit line, solely for a reproductive criterion, on the ability of female rabbits to deal with constrained environmental conditions. Female rabbits from generations 16 and 36 (n=72 and 79, respectively) of a line founded and selected to increase litter size at weaning were compared simultaneously. Female rabbits were subjected to normal (NC), nutritional (NF) or heat (HC) challenging conditions from 1st to 3rd parturition. Animals in NC and NF were housed at normal room temperatures (18°C to 25°C) and respectively fed with control (11.6 MJ digestible energy (DE)/kg dry matter (DM), 126 g digestible protein (DP)/kg DM, and 168 g of ADF/kg DM) or low-energy fibrous diets (9.1 MJ DE/kg DM, 104 g DP/kg DM and 266 g ADF/kg DM), whereas those housed in HC were subjected to high room temperatures (25°C to 35°C) and the control diet. The litter size was lower for female rabbits housed in both NF and HC environments, but the extent and timing where this reduction took place differed between generations. In challenging conditions (NF and HC), the average reduction in the reproductive performance of female rabbits from generation 16, compared with NC, was -2.26 (P<0.05) and -0.51 kits born alive at 2nd and 3rd parturition, respectively. However, under these challenging conditions, the reproductive performance of female rabbits from generation 36 was less affected at 2nd parturition (-1.25 kits born alive), but showed a greater reduction at the 3rd parturition (-3.53 kits born alive; P<0.05) compared with NC. The results also showed differences between generations in digestible energy intake, milk yield and accretion, and use of body reserves throughout lactation in NC, HC and NF, which together indicate that there were different resource allocation strategies in the animals from the different generations. Selection to increase litter size at weaning led to increased reproductive robustness at the onset of an environmental constraint, but failure to sustain the reproductive liability when the challenge was maintained in the long term. This response could be directly related to the short-term environmental fluctuations (less severe) that frequently occur in the environment where this line has been selected.

Effect of feeding diets containing barley, wheat and corn distillers dried grains with solubles on carcass traits and meat quality in growing rabbits

The effect of dietary inclusion of distillers dried grains with solubles (DDGS) on carcass and meat quality of longissimus muscle was studied in 100 growing rabbits from 28 to 59days old. Diets with no DDGS (C), barley (Db20), wheat (Dw20) and corn (Dc20) DDGS at 20% and corn (Dc40) DDGS at 40% were formulated. No effects on most of the carcass traits, texture and water holding capacity were found. Barley and corn DDGS led to a higher dissectible fat percentage. Meat redness was higher with Dw20 and pH was higher with Dw20 and Db20 than with Dc20. Protein and saturated fatty acids concentration declined as corn DDGS level increased. Dc40 led to the lowest saturated/unsaturated fatty acid ratio, atherogenic index and thrombogenic index. In conclusion, dietary inclusion of these DDGS at 20% did not affect most of the carcass and meat quality traits in rabbits.

Attitude Estimation using Low-Cost Sensors: a comparative analysis

In this paper several algorithms to estimate the attitude of a UAS using low-cost sensors are reviewed and a new one including the angular velocity is proposed. The fusion of measurement coming from gyroscopes and accelerometers is based on the Kalman filter. A quadrotor experimental platform is used to compare the measurement systems. The estimation results are evaluated under different conditions and compared against the results obtained with an industrial measurement device.

Determinación de producción de metano en caprinos alimentados con dietas con distintos cereales

Resumen es: Se utilizaron tres cabras primiparas de raza Murciano-Granadina de un ano y medio de edad y en estado de mantenimiento, con un peso medio de 33,08 ± 2,1 ...