The paper reports the profile of individual organic acids and phenolic content in fresh fruit and jam from three populations of cornelian cherry ( Cornus mas L.) wild genotypes originating from Bosnia and Herzegovina. Immediately after harvest, jams were cooked at maximum 80°C from the corresponding fruit. The jam was sampled in five replications at three different storage times for each region: immediately after processing, and then after four and six months of storage, for individual organic acids and phenolics by high-performance liquid chromatography (HPLC). The phenolic compounds found in the fresh fruit were also found in the jams - however, in significantly lower amounts in jam. The three most abundant phenolic compounds found in cornelian cherry fruit as well as in the corresponding jams were procyanidin B1, quercetin 3- O -robinobioside and peonidin 3- O -glucoside. Jam contained dramatically lower levels of phenolic compounds compared to fresh fruit. The most stable phenolic compounds were flavonols where the smallest losses were recorded. The levels of flavan 3-ols, hydroxycinnamicacid, flavonols and anthocyanins declined more during jam processing than during storage, with a significant influence of the growing region.
This paper investigates the genetic based re-planning search strategy, using neural learned vibration behavior for achieving tolerance compensation of uncertainties in robotic assembly. The vibration behavior was created from complex robot assembly of cogged tube over multistage planetary speed. Complex extensive experimental investigations were conducted for the purpose of finding the optimum vibration solution for each planetary stage reducer in order to complete the assembly process in defined real-time. However, tuning those parameters through experimental discovering for improved performance is a time consuming process. Neural network based learning was used to generate wider scope of parameters in order to improve the robot behavior during each state of the assembly process. As a novel modelling formalism of reactive hybrid automata, we propose the Wormhole Model with both learning and re-planning capacities (WOMOLERE). For our application, the states of hybrid automaton include amplitudes and frequencies of robot vibration module. The transition action is a function of minimal distance and uncertainty effects due to jamming during the assembly process. The results suggest that the methodology is adequate and could be recognized as an idea for designing of robot surgery assistance methods, especially in soft-robotics.
This paper presents a novel functional observer for motion control systems to provide higher accuracy and less noise in comparison to existing observers. The observer uses the input current and position information along with the nominal parameters of the plant and can observe the velocity, acceleration and disturbance information of the system. The novelty of the observer is based on its functional structure that can intrinsically estimate and compensate the un-measured inputs (like disturbance acting on the system) using the measured input current. The experimental results of the proposed estimator verifies its success in estimating the velocity, acceleration and disturbance with better precision than other second order observers.
ed/Indexed in Science Citation Index Expanded, SCOPUS, EBSCO and INSPEC (Institution of Electrical Engineers)
A 3-PRR flexure based mechanism which is used as a redundant mechanism providing only x-y micro positioning is designed and controlled in this paper. The aim of this work is to eliminate the unpredictable motions due to manufacturing and assembling errors by implementing sliding mode control (SMC) with disturbance observer (DOB) using piezoelectric actuator models. The system is designed to be redundant to enhance the position control. In order to see the effects of the redundant system firstly the closed loop control is implemented for 2 piezoelectric actuators and the remainder piezoelectric actuator is treated as a fixture. Then the position control is implemented for 3 piezoelectric actuators. As a result, our redundant mechanism tracks the desired trajectory accurately and its workspace is bigger. Finally we have compared the proposed position control with the conventional PID control. It is seen that SMC with DOB gives better results. We have achieved to make the position control of our mechanism, which has unpredictable position errors due to rough manufacturing, assembly, piezoelectric actuator hysteresis etc. The designed 3-PRR flexure mechanism can be used as a micro positioner with the available measurement in the laboratory.
This paper discusses the trajectory generation algorithm, contour error construction method and finally the contour controller design. In the trajectory generation algorithm combination of elliptical Fourier descriptors (EFD) and time based spline approximation (TBSA) is used to generate position, velocity and acceleration references. Contour error is constructed using transformation of trajectory tracking errors. Transformation is computationally efficient and requires only reference velocity information. Contour controller is designed using sliding mode control. Experiments are performed on planar linear motion stage and significant contour error reduction is observed.
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