Manipulator system for the redevelopment of gaps in bricks sewers

At present only small sewers shap can automatically be renewed. Large brick sewers which are often found in nearly every large city still have to be repaired manually. Therefore, the company HOCHTIEF and the Fraunhofer-Gesellschaft have developed a remote-controlled manipulator system. This machine is a hydraulic powered robot with 5 degrees of freedom that automatically cuts out the mortar and refills the grooves. Two CCD-cameras are integrated in the wrist axes, directed at the tool, while a third camera is mounted on the vehicle and gives the operator an overview of the working area. The operator defines, via the TV-image, the edges of the brick sewers that have to be renewed. This operation is mostly computer-aided. The task of the operator is reduced to the monitoring the robot's movement and the correcting the computed robot path with a joystick. Initially the joints are cut by a finger milling cutter, then mortar is pressed into the groove and smoothed. The robot can be dismantl ed and therefore can be transported through manholes with a diameter of 625 mm. The current version was designed for oval sewers with a height of 1400 mm and a width of 850 mm. The robot is mounted on a walking gear to move through the sewer. In a container outside the sewer, control instruments and monitors inform the operator about the state of the machine and the state of the work process

Computer aided remote control for a manipulator system to repair sewers

Remote controlled operation requires a lot of information about the working environment. Cameras and proximity sensors can not give all the information being considered as necessary for working in a narrow and hardly observable environment. If the environment is geometrically more or less defined, computer support can give the missing information. The handling task in this case is the cutting of the old mortar in brick sewers and the replacing of a new one. The sewers have an elliptic cross-section which is exactly mathematically described. Therefore, the handling task can be preplanned by a computer algorithm. During the cutting operation the operator has the possibility to correct the cutter path with a joystick which works in a coordinate frame fitting to the sewer surface. In the first working step the longitudinal gaps are cut and the end points of the transverse gaps are taught. In this way we get a number of path points which have to be combined by a special computer algorithm t o an extended gap-program. The operator has the ability to change the path velocity between 0 % and 100 %; therefore, it can react on unpredictable events. In case of emergency, like breaking of a cutter, the operator can start a interruption routine. After a repairing of the damaged part the automatic program can be restarted at the beginning of a gap. The real manipulator movement will be shown on three video terminals. Additionally, a synthetical two-dimensional representation on a personal computer is available which does not only show the manipulator in the sewers but also the working process and the state of the machine

Manipulatorsystem for the redevelopment of gaps in bricks sewers

Currently only small sewers with symmetrical shap can automatically be renewed. Large brick sewers as we can find in nearly every big town are repaired manually. Therefore the company HOCHTIEF and the Fraunhofer-Gesellschaft have developed a remote controlled manipulator system. This machine is a hydraulic driven robot with 5 d.o.f for the automatically cutting and filling of the brick sewers. Three CCD-cameras inform the operator about the redevelopment process. Two cameras are integrated in the wrist axes and look onto the tool. A third camera is mounted on the vehicle and gives the operator an overview about the working area. The operator defines via the TV-image the edge points of the brick sewers which has to be redevelopped. This teaching process is mostly computer-aided. The task of the operator is reduced to the monitoring of the robot movement and the correction of the computed robot path with a joystick. At first the gaps are cutted free by a finger milling cutter. In the nex t operation mortar is pressed into the gap and smoothed. The robot can be taken into pieces and therefore it can be transported through drains with a diameter of 610 mm. The actual version was designed for oval sewers with a height of 1400 mm and a width of 850 mm. For the movement within the sewer the robot is mounted on a walking mechanism. In a container outside of the sewer control instruments and monitors inform the operator about the state of the machine and the state of the workprocess

Promiscuous enantioselective (−)-γ-lactamase activity in the Pseudomonas fluorescens esterase I

A promiscuous but very enantioselective (−)-γ-lactamase activity in the kinetic resolution of the Vince lactam (2-azabicyclo[2.2.1]hept-5-en-3-one) was detected in the Pseudomonas fluorescens esterase I (PFEI). The lactamase activity was increased 200-fold by the introduction of a point mutation and resulted as enantioselective as the Microbacterium sp. enzyme used industrially in this resolution. The structural and mechanistic determinants for the catalytic promiscuity and enantioselectivity were identified by molecular modeling, setting a ground stone to engineer further amidase-related activities from this esterase.A. H. and J. B. acknowledge funding from the Spanish Ministry of Science (grants BIO2008-01481, RyC2006-02441), an institutional grant from Fundación Ramón Areces to CBMSO and a generous allocation of computing time at the Scientific Computation Center of the UAM (CCC-UAM). A. H. and J. B. are thankful to M. J. de Soto and E. Sánchez for their assistance. J. A. H. acknowledges funding from the Spanish Ministry of Science (grant BFU 2008-01711). N. S.-M. is a fellow of the Fundayacucho Foundation (Venezuela). A. S., M. S. and U. T. B. acknowledge funding from the Deutsche Bundesstiftung Umwelt (Osnabrück, Germany) grant no. AZ13159. We thank Dr Richard Lloyd (Dr Reddy’s, Cambridge, UK) for providing the gene coding for the Microbacterium sp. γ-lactamase, Prof. R. Kazlauskas for the gene encoding the L29P variant of PFEI, and Dr J. A. Gámez for fruitful discussion.Peer reviewe

A one-pot, simple methodology for cassette randomisation and recombination for focused directed evolution

10 pags, 7 figs, 2 tabsProtein engineering is currently performed either by rational design, focusing in most cases on only a few positions modified by site-directed mutagenesis, or by directed molecular evolution, in which the entire protein-encoding gene is subjected to random mutagenesis followed by screening or selection of desired phenotypes. A novel alternative is focused directed evolution, in which only fragments of a protein are randomised while the overall scaffold of a protein remains unchanged. For this purpose, we developed a PCR technique using long, spiked oligonucleotides, which allow randomising of one or several cassettes in any given position of a gene. This method allows over 95% incorporation of mutations independently of their position within the gene, yielding sufficient product to generate large libraries, and the possibility of simultaneously randomising more than one locus at a time, thus originating recombination. The high efficiency of this method was verified by creating focused mutant libraries of Pseudomonas fluorescens esterase I (PFEI), screening for altered substrate selectivity and validating against libraries created by error-prone PCR. This led to the identification of two mutants within the OSCARR library with a 10-fold higher catalytic efficiency towards p-nitrophenyl dodecanoate. These PFEI variants were also modelled in order to explain the observed effects. © The Author 2008. Published by Oxford University Press. All rights reserved.European Commission's Human Potential Programme (HPRN-CT2002-00239); Deutsche Bundestiftung Umwelt (AZ13159); Spanish Ministry of Education and Science (‘Ramón y Cajal’ Programme); ‘Ramón Areces’ Foundation

Entwicklung und Erprobung eines hochflexiblen Handhabungssystems mit großer Reichweite und hoher Nutzlast

Der Beitrag gibt einen Überblick über die Arbeiten des IPA im Rahmen der Entwicklung eines Manipulators mit großer Reichweite und hoher Nutzlast, insbesondere wurden dabei die Mechanik ausgelegt, wesentliche Komponenten der Steuerung und Sensorik entwickelt sowie das Gesamtsystem in Betrieb genommen