MA: Development And Control Of A Delta Kinematic Robot For Haptic Telemanipulation

As part of the Collaborative Research Center (SFB), project A07 is concerned with the development of miniature Lagrangian sensors to determine process variables in fluidized bed reactors in order to enable process control. The sensors are also to be swirled around in the reactor during the process in order to measure parameters such as temperature, humidity and process progress. In contrast to temperature measurement, which can be realized with conventional sensors, the measurement of moisture and process progress is not directly possible. These sensors in development are miniature spheres called Smart Particles.

To determine these parameters, the change in electrical conductance during the process is used. The conductance is dependent on the increasing fluidized bed thickness and the changing water content. Conductance is measured using electrical impedance spectroscopy (EIS), in which a defined current is passed through a substrate while measuring the voltage. A subsequent comparison with a previously measured conductance behavior provides insight into the current reactor state.

A particular challenge in this project is the final assembly of the Smart Particle, as the final version is targeted to be a 5mm sphere in which components such as ASIC chip, electrodes, magnetic particle and maybe more have to be placed precisely and further processes (e.g. soldering, gluing). For this assembly process, a haptic telemanipulation system with force feedback is to be developed. One part of that system is the robot operating the tools (pick and place tools, solder iron) that is controlled by a user through a haptic interface such as the TouchX, which is already available in the institute. One key feature of such a system is the haptic transparency between operator and remote environment, where the user (=human) is known to have a rather small impedance that is best matched by a parallel kinematic robot such as a delta robot.

The task is to develop and implement a delta kinematic robot suitable for this assembly process (research may already give some designs to chose from). A focus is to be set on the different tools that have to be operated and the mechanical impedance during the design. In a next stage, the kinematics of the robot are to be derived to establish rudimentary (open loop)control of the robot (position control). The last step is to map the inputs of the TouchX to the robot hence controlling the robot through the device.

As part of the Collaborative Research Center (SFB), project A07 is concerned with the development of miniature Lagrangian sensors to determine process variables in fluidized bed reactors in order to enable process control. The sensors are also to be swirled around in the reactor during the process in order to measure parameters such as temperature, humidity and process progress. In contrast to temperature measurement, which can be realized with conventional sensors, the measurement of moisture and process progress is not directly possible. These sensors in development are miniature spheres called Smart Particles.

To determine these parameters, the change in electrical conductance during the process is used. The conductance is dependent on the increasing fluidized bed thickness and the changing water content. Conductance is measured using electrical impedance spectroscopy (EIS), in which a defined current is passed through a substrate while measuring the voltage. A subsequent comparison with a previously measured conductance behavior provides insight into the current reactor state.

Eine besondere Herausforderung in diesem Projekt ist die Endmontage des Smart Particle, da die Endversion eine 5 mm große Kugel sein soll, in der Komponenten wie ASIC-Chip, Elektroden, Magnetpartikel und vielleicht noch mehr präzise platziert und weiterverarbeitet werden müssen (z.B. Löten, Kleben). Für diesen Montageprozess soll ein haptisches Telemanipulationssystem mit Kraftrückkopplung entwickelt werden. Ein Teil dieses Systems ist der Roboter, der die Werkzeuge (Pick-and-Place-Werkzeuge, Lötkolben) bedient und von einem Benutzer über eine haptische Schnittstelle wie das im Institut bereits vorhandene TouchX gesteuert wird. Ein wesentliches Merkmal eines solchen Systems ist die haptische Transparenz zwischen Bediener und entfernter Umgebung, wobei der Benutzer (=Mensch) bekanntermaßen eine eher geringe Impedanz hat, die am besten von einem parallelkinematischen Roboter wie einem Deltaroboter erfüllt wird.

Die Aufgabe besteht darin, einen deltakinematischen Roboter zu entwickeln und zu implementieren, der für diesen Montageprozess geeignet ist (die Forschung kann bereits einige Entwürfe zur Auswahl liefern). Bei der Konstruktion ist ein Schwerpunkt auf die verschiedenen zu bedienenden Werkzeuge und die mechanische Impedanz zu legen. In einem nächsten Schritt soll die Kinematik des Roboters abgeleitet werden, um eine rudimentäre (open loop) Steuerung des Roboters (Positionssteuerung) zu etablieren. Der letzte Schritt besteht darin, die Eingänge des TouchX auf den Roboter abzubilden, so dass der Roboter über das Gerät gesteuert werden kann.