E&S Program Paper Accepted for IROS 2018 (International Conference on Intelligent Robots, Madrid, ES)

A paper, from the Ergonomics & Safety Program, has been accepted for the 2018 International Conference on Intelligent Robots (IROS 2018) entitled Dynamics Model Learning and Manipulation Planning for Objects in Hospitals Using a Patient Assistant Mobile (PAM) Robot, by Roya Sabbagh Novin, Amir Yazdani, Tucker Hermans, and Andrew Merryweather.  This conference will be held in Madrid, Spain on October 1-5, 2018.


One of the most concerning and high-cost problems in hospitals is patients falls. We address this problem by introducing PAM, a patient assistant mobile robot that delivers a mobility aid and helps with fall prevention. Common objects found in indoor environments such as hospitals include objects with legs (i.e. walkers, tables, chairs, equipment stands). For a mobile robot operating in such environments, safely maneuvering these objects without collision is essential. Since providing the robot with dynamic models of all possible legged objects that may exist in such environments is not feasible, learning models that can be used in manipulation planning that estimate an object’s dynamics is useful. We describe a probabilistic method for this by fitting pre-categorized object models learned from minimal force and motion interactions with an object. The multiple options for grasping legs requires a control system comprised by a hybrid of discrete grasping legs and continuous applied forces. To do this, a model of a simple one-wheel point-mass is used. A hybrid MPC-based manipulation planning algorithm was developed to compensate for modeling errors. While the proposed algorithm is developed for a wider range of legged objects, we will focus on the case of a 2-wheel walker in this paper. Simulation and experimental tests show that the obtained dynamic model is sufficiently accurate for safe and collision-free manipulation. When combined with the proposed manipulation planning algorithm, the robot can successfully move the object to a desired position.

Jon Mortensen presented his poster at ASB 2017

downloadJon Mortensen presented his research of modeling directional neck stiffness and muscle coactivation in OpenSim at the American Society of Biomechanics (ASB 2017) conference in Boulder, Colorado. The presentation was well received and there was  a lively question and answer session. Dr. Merryweather and Kyle Christian also attended the conference.    IMG_20170810_105454220

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Maggie Patterson and Dr. Hang Xu presented in GCMAS 2017

Maggie Patterson, an undergraduate member of laboratory presented in 2017 Gait and Clinical Movement Analysis Society annual conference with the title of “Using Motion Capture Techniques to Improve the Gait Therapy Options for Patients with Parkinson Disease”. Dr. Hang Xu, former PhD member of the Lab. also presented there with the title of “Vacuum Level Effects on Knee Contact Force for Unilateral Transtibial Amputee with Elevated Vacuum Suspension”.


7th World Congress of Biomechanics


The World Congress of Biomechanics is an international biomechanics conference that is held once every four years. Its location alternates between Europe, Asia, and the Americas.

This year, among the nearly 4000 attendees was a large number of students and faculty from the Department of Mechanical Engineering. Among these were individuals from the Ergonomics and Safety (E&S) lab. E&S Lab Director Dr. Andrew Merryweather, and students Marissa Christman, MaryEllen Hunt, Rami Shorti, and Krytopher Tung participated with poster presentation at the conference. Christopher Wilson, a PhD student in Rehabilitation Sciences currently collaborating with E&S, accompanied the group and presented efforts from a collaborative grant evaluating Hospital Bed Safety (AHRQ 1R01HS018953-01).

From Left to Right: Rami Short, Dr. Merryweather, MaryEllen Hunt, Kryztopher Tung, Marissa Christman, Chris Wilson attending the 7th World Congress of Biomechanics in Boston, July 2014.
From Left to Right: Rami Short, Dr. Merryweather, MaryEllen Hunt, Kryztopher Tung, Marissa Christman, Chris Wilson attending the 7th World Congress of Biomechanics in Boston, July 2014.
Please use the following links to read more about what was presented from our research group:
  • Kinematic analysis of sit-to-walk movement in a fall prone population Abstract/Poster (Presented by Marissa Christman)
  • Characterization of Gait Over Irregular Terrain to Inform a Virtual Reality Rehabilitation Environment Abstract/Poster (Presented by MaryEllen Hunt)
  • Evaluation of an Ergonomic Laparoscopic Handle Design and Upper Extremity Musculoskeletal Disorder Risk Factors Abstract/Poster (Presented by Kryztopher Tung)
  • Patient Mobility in Hospital Beds With and Without Side Rails Abstract/Poster (Presented by Christopher Wilson)