Method of analysis of the current state of inertial characteristics of an autonomous mobile robot of variable configuration

The features of the dynamics of an autonomous mobile robot (AMR) of variable configuration with the relative movement of attachments are considered. Analysis of the current state of inertial characteristics during AMR operation will ensure stable movement along a given trajectory, successful implementation of technological operations by attachments, and preservation of the robot's functionality when operating under undetermined or extreme conditions. At the design stage, the analysis of the inertial characteristics of the AMR will make it possible to refine the parameters of the mathematical model, improve the algorithms for adaptive control and correct the commands for the actuators. Figs.: 2. Tabl.: 2. Bibliogr.: 10 titles. Keywords: autonomous mobile robot, inertial characteristics.

Design and kinematic modeling of an origami-inspired cable-driven flexible arm

The cable-driven flexible arm based on the principle of origami is a new type of non-articulated compliant actuator with high integration, high environmental adaptability, large workspace/large deployment ratio. The forward/reverse kinematic models of joint space, operation space and driving space along with trajectory error model of the cable-driven flexible arm were proposed in this paper. The prototype of the flexible arm was developed capable of realizing bending, torsion and expansion/contraction. The simulation and experiment results of the cable-driven foldable flexible arm verified feasibility of the kinematic models and driving method proposed in this paper. Above research achievements lay necessary foundation for the next step to realize the key service functions of grasping/manipulation, three-dimensional precise movement, non-structural environment interaction/adaptation of the flexible arm with variable stiffness, variable configuration and variable size.

Improving implicit geologic models based on data configuration

<p>Implicit methods have been the basis of many developments in 3-D structural geologic modeling.  Typical input data for these types of models include surface points and orientations of geologic units, as well as the corresponding age relations (stratigraphic pile). In addition, the range of influence of input points needs to be defined, but it is difficult to infer a reasonable stationary estimate from data with highly variable configuration.</p><p>Often, this results in models that show artefacts due to data configuration including oversimplified results (underfitting) in areas where data is missing, overcomplex results (overfitting) in areas of high data density and geologically unreasonable surface shapes.</p><p>In this work we explore various methods to improve 3-D implicit geologic modeling by manipulating the data configuration using locally varying anisotropic kernels and kernel density estimation. In other words, the influence of input data in the interpolation is weighted based on directions and data density. Input parameters for these methods can either be based on the original input data configuration, inferred from additional supportive data, or be based on geologic expert knowledge. The proposed methods aim to increase model control while retaining the key advantages of implicit modeling.</p><p>Model improvements will be shown using a set of typical geologic structures and regularly occurring artefacts. We compare results to previously proposed methods that integrate anisotropies in traditional kriging applications and discuss the specific requirements for applicability in implicit structural geomodeling.</p>

On algebraic integrals of equations of motion of a complex mechanical system

Criteria for the existence of certain types of algebraic first integrals of the equation of motion of a mechanical system of variable mass composition and variable configuration are given. The carrier body of the system (base body) rotates around a fixed pole in a stationary homogeneous gravity field under the influence of specified nonstationary forces. The types of partial integrals are indicated and restrictions are established that determine their existence.

The field of algebraic integrals of equations of motion of a complex mechanical system

Criteria for the existence of certain types of algebraic first integrals of the equation of motion of a mechanical system of variable mass composition and variable configuration are given. The carrier body of the system (base body) rotates around a fixed pole in a stationary homogeneous gravity field under the influence of specified nonstationary forces. The types of partial integrals are indicated and restrictions are established that determine their existence.

Development of variable-configuration wheeled driving system for enhancing the obstacle-crossing ability of unmanned vehicles

A variable-configuration wheeled driving system is proposed to improve the obstacle-crossing abilities of unmanned vehicles. The effects of the wheel load on the wheels’ obstacle-crossing abilities are analysed using statics theory. Similarly, the effects of the suspension’s stiffness and the adhesion coefficient on the vehicle’s obstacle-crossing ability are analysed. Numerical calculation results show that a higher wheel lift height leads to improved obstacle-crossing abilities. A strategy to adjust the system configuration during obstacle crossing is designed with the wheel lift height acting as the optimisation target. The variable-configuration strategy is verified and the optimal adjustment of the middle axle is determined through simulations. An obstacle-crossing experiment shows that a vehicle can cross a 1-m step obstacle when the proposed variable-configuration strategy is applied. The obstacle-crossing ability of the unmanned vehicle can thus be greatly enhanced.

Analytical Study of Front-End Circuits Coupled to Silicon Photomultipliers for Timing Performance Estimation under the Influence of Parasitic Components

Full exploitation of the intrinsic fast timing capabilities of analog silicon photomultipliers (SiPMs) requires suitable front-end electronics. Even a parasitic inductance of a few nH, associated to the interconnections between the SiPM and the preamplifier, can significantly degrade the steepness of the detector response, thus compromising the timing accuracy. In this work, we propose a simple analytic expression for the single-photon response of a SiPM coupled to the front-end electronics, as a function of the main parameters of the detector and the preamplifier, taking into account the parasitic inductance. The model is useful to evaluate the influence of each parameter of the system on the slope of its response and to guide the designer in the definition of the architecture and the specifications for the front-end electronics. The results provided by the model have been successfully compared with experimental measurements from a front-end circuit with variable configuration based on a bipolar junction transistor (BJT), coupled to a 3 × 3 mm2 SiPM stimulated by a fast-pulsed laser source.

Robustness Optimization of an Existing Tablet Coating Process Applying Retrospective Knowledge (rQbD) and Validation

The objective of these studies is to verify and validate the improvement in the inter-tablet coating uniformity for an industrially commercialized coated tablet, without involving changes in the approved registration dossier. Using the CPP (critical process parameters) determined from previous retrospective statistical analysis, the recommended working ranges are identified. Retrospective analysis showed that the design of experiments (DoE) provided an improved process variable configuration. Therefore, it is decided to study two critical parameters: Product temperature and drum speed, with an additional 22 experimental design. The quality results of the samples analyzed show that the aesthetic defects of the batches made with the new working ranges have been reduced. These results have also been corroborated with the 42 industrial batches manufactured with the new ranges. With the optimized parameters, tablets have been coated and the suitability of the model determined. The results demonstrated the overall reliability and effectiveness of the proposed Quality by Design approach and provides a useful tool to help optimize the industrial coating process. This study confirms that it is possible to optimize and validate the manufacturing process of an existing commercial product by means of a DoE with retrospective data. Therefore, no variation in the dossier is required.