RHOMBUS Home Page

The Setting:

The RHOMBUS project is one of several ongoing projects in the d'Arbeloff Laboratory for Information Systems and Technology in the Department of Mechanical Engineering. at the Massachusetts Institute of Technology. It is funded by the Total Home Automation and Health Care/Elder Care Consortium.

The Concept:

RHOMBUS stands for Reconfigurable Holonomic Omnidirectional Bed with Unified Seating. The idea of this project is to completely eliminate the need for bed to wheelchair transfer for the bedridden person. RHOMBUS accomplishes this by functioning as a bed which transforms into a wheelchair.

The System:

In the bed mode, RHOMBUS is docked with a U shaped bed station and functions as an ordinary twin-sized bed.
RHOMBUS automatically transforms by simultaneously raising the backrest and armrests, lowering the legrest, and undocking from the bed station.
By the time RHOMBUS has reconfigured into a chair, it has completely undocked from the bed station and is ready for use as a motorized wheelchair. To return to bed mode, the procedure is reversed. Force sensing bumpers at the base of the chair are use to compliantly dock the chair into the bed station. The chair is also capable of automatic docking over top of a standard wall mounted toilet. A trap door will open in the seat, allowing the patient to use the toilet without getting off of the chair. 
In the wheelchair mode, RHOMBUS is completely independent and capable of omnidirectional navigation within the home environment. The chair is controlled by an onboard PC computer and can be driven manually using either a joystick or pressure sensitive footpads, or driven automatically by having the computer execute a preplanned route. A teleconferencing/control panel hangs within arms reach allowing the occupant to communicate with a remote caregiver and control the chair through graphical user interface.

Subsystems:

The vehicle:

The drive platform for RHOMBUS is a holonomic omnidirectional ball-wheeled vehicle. It is capable of any combination of arbitrary instantaneous velocities in the plane of the floor. With 3 degrees of freedom, it is well suited for performing rigid docking with various stations within the home. 

The chair:

A five degree of freedom chair has been developed which allows the patient to be moved from lying position to sitting position. The chair can be raised vertically as well as tilted back and forth, and can even raise the patient to a standing position.

The Research Staff:

The following people at MIT are involved with the RHOMBUS project:
  • Haruhiko H. Asada, Ford Professor of Mechanical Engineering, Director of d'Arbeloff Lab

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  • Stephen Mascaro, Graduate Research Assistant
  • Joseph Spano, Graduate Research Assistant
    • Email: asada@mit.edu, smascaro@mit.edu, spano@mit.edu

    Publications:

  • Mascaro, S. "Force Guided Docking Control of an Omnidirectional Holonomic Vehicle and its Application to Wheelchairs," M.S. Thesis, Massachusetts Institute of Technology, Feb 1997.

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  • Spano, J. "Design and Control of a Reconfigurable Bed/Chair System with Body Pressure Sensing," M.S. Thesis, Massachusetts Institute of Technology, Feb 1997.

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  • Mascaro, S., Spano, J., and Asada, H., 1997, "A Reconfigurable Holonomic Omnidirectional Mobile Bed with Unified Seating (RHOMBUS) for Bedridden Patients," Proceedings of the IEEE International Conference on Robotics and Automation, Vol. 2, pp. 1277-1282.

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  • Mascaro, S., and Asada, H., 1997, "A Hybrid Bed/Chair System for Bedridden Patients - Elimination of Transfer Between a Bed and Wheelchair," Proceedings of the ASME Dynamic Systems and Control Division, Vol. 61, pp. 393-400.

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  • Mascaro, S., and Asada, H., 1998, "Docking Control of Holonomic Omnidirectional Vehicles with Applications to a Hybrid Wheelchair/Bed System," Proceedings of the IEEE International Conference on Robotics and Automation, Vol. 1, pp. 339-405.


    • Last modified: July 15, 1999 / smascaro@mit.edu