Fraunhofer-Institut für Produktionsanlagen und Konstruktionstechnik IPK

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  • Publication
    Adaptive backstepping controller with Kalman state estimator for stabilisation and manoeuvre of pedestrian controlled uniaxial transport vehicles
    ( 2015)
    Brüning, M.
    ;
    Thiele, Gregor
    ;
    Schönewolf, W.
    ;
    Krüger, J.
    Pedestrian controlled uniaxial vehicles for goods transport such as hand trucks offer intuitive manoeuvrability with little space requirements. The disadvantage of this class of statically underdetermined vehicles is the need for the user to apply force for both stabilisation and propulsion. Removing this disadvantage is the key to enable their use for convenient transportation of heavy goods over long distances. For this our solution approach is to equip the vehicle with controlled drives providing force for both balancing and propulsion. Different to uniaxial vehicles without payload or for passenger transportation controller's adaptation to kinematic and dynamic parameters is required here after every reload. The frame's pitch angle must be adapted with every change of load whereby the COG's position is not measurable with acceptable effort. Dynamic parameters vary in a wide range. We applied an adaptive controller based on backstepping combined with Kalman state estimation for stable balancing with adaptation to changed payload without need for external support from the user. The manoeuvre concept based on low interaction forces applied from the user to the vehicle frame is taking advantage of the underconstrained dynamics of the vehicle, and offers similar driving behaviour to the user with different load situations. Operating control levers for setting speed is not required. To allow for cheap production a design goal was not requiring sensor information of both load's absolute weight and user interaction forces. The adaptive control and state estimation concept was simulated based on the kinematic and dynamic model of our new uniaxial vehicle system designed for urban parcel distribution on foot. Simulation results show the correct operation of the approach.
  • Publication
    Stabilisation and manoeuvre of electrically powered pedestrian controlled uniaxial vehicles for goods transport
    ( 2014)
    Brüning, M.
    ;
    Schönewolf, W.
    ;
    Krüger, J.
    Uniaxial vehicles for goods transport such as hand trucks are popular with many transport tasks. They offer intuitive manoeuvrability with little space requirements. The disadvantage of this class of pedestrian controlled means of transportation is the need for the user to apply force for stabilisation and propulsion. To eliminate this disadvantage a solution approach is to equip the vehicle with a controlled drive system providing force for both balancing and propulsion. To make possible stabilisation of a uniaxial vehicle for goods transport without need for external support the frame's pitch angle must be adapted with every change of load, which is a fundamental difference to uniaxial vehicles without payload or for passenger transportation. To make possible intuitive and convenient pedestrian controlled manoeuvre even with high payload the controller must set translational and rotational speed based on low interaction forces applied by the user going along. To allow for cheap production we developed a balance and manoeuvre controller not requiring sensor information of both load's absolute weight and user interaction forces. Main components of the concept are a balance controller including a Kalman state estimator for identification of frame's and load's combined centre of gravity's pitch angle, a manoeuvre controller based on state space control and a sophisticated program sequence switching automatically between operating modes for reload and manoeuvre. The control concept was designed and implemented using our new uniaxial vehicle system for urban goods transport. This vehicle is the first electrically powered hand truck that both balances adaptive to changing payload and allows for pedestrian controlled manoeuvre without need to operate control levers for setting speed or steering angle. The experimental results presented in this paper show the correct operation of the approach.
  • Publication
    Freight transport system for urban shipment and delivery
    ( 2011)
    Brüning, M.
    ;
    Schönewolf, W.
    Many problems with present conventional delivery scenarios in urban areas are caused by use of conventional vehicles. These problems are amongst others limited efficiency, ecological damages, disturbance of moving traffic and pedestrians and difficulties to comply with environmental and traffic regulations, affecting local communities, business people and their customers as well as the logistic companies. Courier, Express & Parcel (CEP) providers are obliged to use conventional cars and vans due to the lack of specialized solutions. Therefore our approach is improvement of urban shipment and delivery based on existing infrastructure by means of an innovative vehicle concept. Core of the developed transport system is a uniaxial transport unit, designed for application both as part of a multiple trailer vehicle and for use as separate hand-guided transportation unit. The concept was developed based on a catalog of requirements for a vehicle for urban shipment and delivery, a result from the EU research project FIDEUS. The developed concept satisfies all formulated demands. A test vehicle of the transport system was built. Current research focuses on controller synthesis and implementation. The next step intended is execution of field tests involving logistic companies to prove the vehicle system's suitability for daily use and to discover potential for improvement.
  • Patent
    Multifunktionales Transportsystem mit mehreren fahrbaren Transporteinheiten
    ( 2011)
    Schönewolf, W.
    ;
    Brüning, M.
    ;
    Uhlmann, E.
    The invention relates to a multifunctional transporting system with multiple drivable transporting units (1), each of which has a coupling device (5) in a front and a rear region, said transporting units (1) being coupleable to one another and/or to a guiding vehicle (6) by means of the coupling device. The transporting units (1) can be removed or decoupled from the transporting system as closed units. For this purpose, the units have at least one handle (8) in addition to the couplings, said units being manually guidable by an operator (7) in the decoupled state by means of the handle such that the mail items to be transported can remain on the transporting unit until delivery without manually transferring or transporting. In particular, the delivery of parcels in the city-center area is implemented in a more efficient manner and thus in a more inexpensive and environmentally-friendly manner using the proposed transporting system.
  • Publication
    Richtlinien für die Gestaltung von visuellem Biofeedback in der neurologischen Gangrehabilitation nach Schlaganfall
    ( 2010)
    Brüning, M.
    ;
    Hussein, S.
    ;
    Bardeleben, A.
    ;
    Schmidt, H.
    ;
    Krüger, J.
    ;
    Hesse, S.
  • Publication
    Visuelles Biofeedback für die gerätegestützte neurologische Gangrehabilitation nach Schlaganfall
    ( 2010)
    Brüning, M.
    ;
    Hussein, S.
    ;
    Bardeleben, A.
    ;
    Schmidt, H.
    ;
    Krüger, J.
    ;
    Hesse, S.
  • Publication
    Structural analysis method for optimized design of complex kinematic structures using static and dynamic models and application to a robotic walking simulator
    ( 2010)
    Brüning, M.
    ;
    Hussein, S.
    ;
    Schmidt, H.
    ;
    Krüger, J.
    This paper describes an approach for structural analysis for design improvements of complex, e.g. hybrid, kinematic structures utilizing static and dynamic models. It is suitable to locate improvement potentials in existing mechanisms, facilitate goal-oriented design of new mechanisms or for a simulation-based controller synthesis e.g. a compliance-controller. To receive a model close to reality, mechanical influences, which are commonly neglected in conventional robot models, are analyzed regarding their relevance and if suitable integrated into the model. Investigated effects are the mechanical compliances of links and gears, compliances of the actuators resulting from the control circuits as well as non-linear frictional influences of the actuators. The kinematic and dynamic model is realized as an iterative solution instead of a closed analytic solution with extensive symbolic expressions. This leads to an analysis with clearly arranged aspects, further more the model is suitable for usage in a real-time control. The mechanical influences are analyzed analytically. The derived dynamic modeling is based on the Newton-Euler formulation. The approach is applied to the robotic walking simulator HapticWalker, a device for robot assisted gait rehabilitation. It consists of two identical hybrid parallel-serial manipulators. The forces calculated by the use of the developed model are in a good congruence with measured values. An obviously improved correspondence between measured and calculated values is achieved by the non-linear friction model of the actuators.