This paper deals with generally routed, pre-bent cable-driven continuum robots (CCR). A CCR consists of a flexible backbone to which multiple disks are attached. Cables are passed through holes in the disk, and when pulled, the flexible backbone and the CCR can attain different shapes based on their routing and backbone configuration. An optimization-based approach, using minimization of strain energy, is shown to give good results for the pose and motion of the CCR and to determine contact with external objects. The pose, motion, and the contact obtained from the model are shown to match very well with experimental results obtained from a 3D-printed CCR. An algorithm is proposed to generate the pre-bent backbone for a CCR which on actuation can attain the desired shape. Using the algorithm, three 3D-printed CCRs with pre-bent backbones are fabricated and these are used to demonstrate a compliant gripper that can grip a spherical object similar to that done by tentacles, and another three-fingered gripper with straight backbone CCRs is used to orient a square object gripped at the end.

Large eddy simulations are performed to investigate the impact of a solid obstacle on the flow around a multiperforated plate typical of aeronautical combustion chambers. The reference configuration is a perforated plate with approximately 200 holes immersed between a cold vein and hot vein at a typical operating point of helicopter combustors. The micro-jet Reynolds number is of the order of 4000, while the blowing and momentum ratios are close to 4 and 8, respectively. A variant configuration is considered that features an additional cylindrical obstacle located in the cold vein and mimicking a spark plug. The study reveals that, downstream of the obstacle, the cooling effectiveness of the plate is reduced by approximately 40 % compared with the reference case, mainly due to the absence of perforation at the obstacle location. The mass flow rate within the holes in the wake produced by the obstacle is reduced by 7 %, which is likely to locally influence the plate cooling. The reduction is attributed to the wake's pressure loss and its impact on the discharge coefficient. Additionally, the cooling effectiveness outside the wake shows a 5 % increase that can be linked to the mass flow rate increase within corresponding holes.

La présente étude visait à documenter l’implantation de l’Accompagnement-citoyen personnalisé d’intégration communautaire (APIC), lors duquel des bénévoles soutiennent la participation sociale d’aînés, dans des organismes communautaires en identifiant les facteurs favorables et défavorables ainsi que ses conditions essentielles. Soutenu par un devis qualitatif descriptif de type recherche clinique, une rencontre et six entretiens semi-dirigés ont été réalisés afin de documenter cette implantation dans six organismes communautaires œuvrant en milieu urbain au Québec (Canada). Selon les six coordonnatrices de l’APIC, les cinq directeurs généraux et l’agente de recherche, le principal facteur favorable est la conviction des responsables de l’implantation en la valeur ajoutée de l’intervention, incluant sa concordance avec la mission et les valeurs des organismes et les besoins de la population qu’ils desservent. Les facteurs défavorables sont principalement la répartition aléatoire et le temps accordé pour l’implantation. Ces résultats permettront de mieux guider l’implantation de l’APIC à plus grande échelle.

Cette étude visait à identifier les facilitateurs, les obstacles et la faisabilité d’implanter un Accompagnement-citoyen personnalisé d’intégration communautaire (APIC) pour des aînés en perte d’autonomie et vivant dans la communauté. L’APIC est un suivi hebdomadaire de trois heures réalisé par un accompagnateur non professionnel formé et supervisé qui vise à optimiser la réalisation d’activités sociales et de loisirs de personnes ayant des incapacités. Une recherche-action a permis de réaliser des entretiens semi-dirigés auprès de 16 participants de la communauté. Les principaux facilitateurs de l’implantation sont l’adaptabilité de l’APIC et son appui scientifique, la reconnaissance d’un besoin, l’expertise et la collaboration. La présence de leaders ouverts à la nouveauté et d’individus offrant du soutien est favorable. Le financement de l’implantation, associé à un contexte économique défavorable, est un obstacle. La majorité des participants perçoivent qu’il serait faisable d’implanter l’APIC en l’intégrant à des structures bénévoles déjà existantes. Ces connaissances permettront d’optimiser l’implantation de l’APIC ou d’interventions similaires dans la communauté.

We present an algorithm for offsetting the workspace obstacles of a circular robot. Our method has two major steps: It finds the raw offset curve for both lines and circular arcs, and then removes the global invalid loops to find the final offset. To generate the raw offset curve and remove global invalid loops, O(n) and O((n+k)log m) computational times are needed respectively, where n is the number of vertices in the original polygon, k is the number of self-intersections and m is the number of segments in the raw offset curve, where m ≤ n. Any local invalid loops are removed before generating the raw offset curve by invoking a pair-wise intersection detection test (PIDT). In the PIDT, two intersecting entities are checked immediately after they are computed, and if the test is positive, portions of the intersecting segments are removed. Our method works for conventional polygons as well as the polygons that contain circular arcs. Our algorithm is simple and very fast, as each sub-process of the algorithm can be completed in linear time except the last one, which is nearly linear. Therefore, the overall complexity of the algorithm is nearly linear. By applying our simple and efficient approach, offsetting obstacles of any shape make it possible to construct a configuration space that ensures optimized motion planning.

In this study a double two-inlet Y-type microchannel with two up-down symmetrical obstacles was applied. This was done because the positions of the obstacles in the flow channel, arranged in an up- down symmetrical fashion, could provide a higher mixing efficiency. As for the optimal layout of obstacles inthe microchannel, the positions of the two up-down symmetrical obstacles were set as the location of obstacle A/D = 0.198, the length of obstacle K/D = 0.453, the horizontal spacing between the two obstacles T/D = 0, and the flow channel width between the two obstacles Y/D = 0.080, This was because it could generate theflow mixing efficiency with 0.984 and at a lower Reynolds number, Re 4.7. These observations willcontribute to the improvement of a Y-type micromixer design.

The aim of this article is to give a regularization method for an unilateral obstacle problem with obstacle ψ and second member f, which generalizes the one established by the authors of [4] in case of null obstacle and a second member is equal to constant 1.