Precision-robotics
Robots are frequently applied in industry and much research is done on many places on extending its use in more domestic environments where contact with people cannot be avoided. This poses severe constraints on safety but also on reliability and precision of operation. The focal point of our research is on precision and in principle a modern industrial robot is a real precision instrument by virtue of an extremely stiff construction and powerful actuation systems with a fast and accurate controller. These are all factors that reduce the safety in a human environment for which reasons more lightweight, compliant structures are preferred with soft edges and low-stiffness control and this all comes at a sacrifice in precision.
The research in our group focuses on the goal to achieve precision in lightweight robots without sacrificing safety.
One example of this research is a haptic master-slave robot for micro-assembly of miniaturised parts. The haptic master should be compatible with the human operator without the possibility to cause harm but also without sacrifice on precision. This research has resulted in new mechanisms where the actuation and sensing is remote from the human operator and where the lowest mass is possible.
Mechatronic optimal design of parallel haptic master devices
The objective of this research is to develop principles for optimal mechatronics design of haptic parallel master devices. To achieve this goal, insights from systems engineering, mechatronics and optimization theory will be combined and the research will be done in close collaboration with other researchers and industry involved in the H-Haptics project.
PhD Thesis: Parallel manipulators with two end-effectors
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- PhD student: Ir. A.G.L. Hoevenaars (Teun)
- Supervisor: Prof.dr.ir. J.L. Herder
- Promotor: Prof.dr.ir. J.L. Herder
- Duration: 2012-2016
This research is part of the H-Haptics programme (www.h-haptics.nl). H-Haptics is a large multi-disciplinary research programme in the Netherlands that aims to develop Human-centered Haptic devices, which assist humans in performing a wide variety tasks.
More specifically, this research is centered around the master device, which forms the haptic interface between the telemanipulation system and the human operator. The project will apply novel insights from both parallel robotics and shared control to develop master devices with unprecedented transparency and increased situational awareness.
Supported by
Haptic slave robot
This project investigates ways to support a human micromanipulation operator in a haptic teleoperation scenario, from a human centered perspective. The project encompasses the analysis of the micromanipulation process, multimodal interaction and support strategies, but also the design of hardware components like force sensors and positioning stages.
PhD Thesis: Slave-side devices for micromanipulation in a haptic teleoperation scenario
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- PhD student: Pablo Estevez
- Supervisor: dr.ir. M. Tichem
- Promotor: Prof.ir. R.H. Munnig Schmidt
- Duration: 2007-2011
Manual manipulation is presently the main method used in the assembly of small series of microproducts. However, human operators often lack the resolution in force application and positioning required by such tasks.
Tele-operated systems with force feedback become then a promising approach. The presence of the human operator gives flexibility to the system, the robotic actuators achieve the required resolution, and the haptic-feedback reduces the risk of damaging handled parts and limits the assembly time.
This PhD project focuses on understanding how is it possible to support the human operator of such a system in order to improve his performance. Several operation modes are considered, spanning from semi-automation to full manual control, and including multimodal feedback channels (visual information, force feedback, auditory signals, etc.). System requirements are generated based on the intended operation mode, and on the constrains imposed both by the operator and the task. Following such requirements, two main hardware components of the slave system are being developed for this application.
Force sensing is a prerequisite of many force feedback schemes. Therefore, a silicon based 6DOF force and torque sensor was designed and fabricated. An asymmetric geometry was selected, leaving one side open for placing tools such as probes or micro grippers. Depending on the axis, the range of the sensor reaches 4 to 30mN in forces and 4 to 40 µNm in torques. Standard deviations up to 14 to 36 µN and 9 to 40 nNm have been observed in the measured data, respectively.
A second component been developed is the high resolution positioning stage. With the aim of minimizing play and achieving a resolution below the micrometer, designs based on flexures hinges and magnetic levitation have been considered. Additionally, the aforementioned principles can be operated with low stiffness or in direct force control, contributing to protect the fragile components and allowing for the implementation of different haptic teleoperation control schemes. Both designs have been optimized to cover a sub-millimeter range with sub-micrometer resolution, moving small payloads of a few grams and applying forces in the mN range.
Publications
- Estevez, P., S. Khan, P. Lambert, M. Porta, I. Polat, C. Scherer, M. Tichem, U. Staufer, H. Langen, and R. Schmidt. “A Haptic Tele-operated System for Microassembly.” Precision Assembly Technologies and Systems (2010).
- Estevez, Pablo, Marcel Tichem, and Robbert Munnig Schmidt. “Concept for a teleoperated micromanipulation station with a magnetically levitated stage and piezoresistive force sensing.,” MicroNano Conference 2010.
- Khan, S., T. de Boer, P. Estevez, H. Langen, and R. Munnig Schmidt. “Development of Haptic Microgripper for Microassembly Operation.” Haptics: Generating and Perceiving Tangible Sensations (2010).
- Lambert, Patrice, Pablo Estevez, Shahzad Khan, Hans Langen, Robbert Schmidt, Marcello Porta, Marcel Tichem, Urs Staufer, Ilhan Polat, and Carsten Scherer. “Progress on Haptic Teleoperation for Micro-assembly,” MicroNano Conference 2009.
- J. Bank, “Development of a novel 6 DOF interaction force sensor for micro-gripper applications.,” MSc Thesis, 2010.
- R.H.S. Bruinen, P. Estevez, R.H. Munnig Schmidt. "Design and analysis of a flexure based 3-DOF micropositioner for haptic teleoperated micromanipulation".
Related projects
- Haptic Teleoperation for Microassembly - Master Device (Patrice Lambert)
- Robust control for haptic teleoperation (Ilhan Polat - DCSC)
Supported by
Wearable arm orthosis for Duchenne patients
This project project aims to develop an inconspicuous body-bound assistive device that can be worn underneath clothing and supports the arm for the independent execution of essential activities of daily living.
PhD Thesis: Slender Spring Systems, for a close-to-body dynamic arm support for people with Duchenne muscular dystrophy
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- PhD student: Ir. A.G. Dunning (Gerard)
- Supervisor: Prof.dr.ir. J.L. Herder
- Promotor: Prof.dr.ir. J.L. Herder
- Duration: 2011-2015
Boys with Duchenne Muscular Dystrophy (DMD) gradually lose the ability to use their muscles as they grow older. As a consequence, functional abilities of the arms decrease up to the point that no arm function is left. The disease affects approximately 1 in every 3,500 live male births. With increasing life expectancy, the preservation of functional abilities in boys with DMD becomes increasingly important. Although some devices aim to compensate for the loss of muscle function, these are not always adequate and are highly stigmatizing.
Therefore, the A(bility)-Gear project aims to develop an inconspicuous body-bound assistive device that can be worn underneath clothing and supports the arm for the independent execution of essential activities of daily living.
Supported by