Mobility and AAL – a Contradiction?
Challenges for Indoor and Outdoor Mobility Assistance

The physical and cognitive conditions of seniors still living at home, possibly with daily care support, or in dedicated residential homes vary considerably, ranging over mild versions of impaired gait or unstable balance, visual impairments, or cognitive indispositions such as spatial disorientation. Our aim is to compensate for declining physical and cognitive capabilities by user-centred development of modular navigation assistants for various mobility platforms, such as walkers or wheelchairs, providing sustained everyday mobility and autonomy with seamless transition from indoors to outdoors in environments such as residential complexes or the neighbourhood quarter; the common paradigm is to only assist when necessary and to permit the user to act independently otherwise.

DFKI has more than 15 years of experience in building smart assistive systems, for electric wheel­chairs (Rolland) and walkers (iWalker), similarly equipped with sensors and motorised rear wheels. For these, a number of assistants for indoor environments have been developed: The Safety Assistant brakes automatically to avoid collisions with obstacles, the Driving Assistant proactively corrects the driving direction to avoid obstacles by controlling the drive, steering and braking accordingly. Rolland and iWalker are equipped with wheel encoders on the back wheels for odometry, a netbook PC for interaction with the user, and laser scanners.

In contrast to young persons, elderly persons with declining vision are less likely to learn the usage of stan­dard aids for the blind. For these, the walker platform, in particular, should provide excellent obstacle avoidance and guidance, in particular when equipped with a natural language interface. The challenge is to support seamless moving from indoor to selected outdoor environ­ments; the precise limitations will have to be defined by careful field trials with end-users.

The Navigation Assistant allows automated driving (without manual steering) to a specified target location in a charted indoor envi­ronment. For outdoor navigation, additional sensors such as differential GPS receivers (which cannot be used indoors) will have to be added, and the software adapted accordingly.

The vision of a personal service or companion robot becomes even more prominent, when interaction with an intelligent environment is added. This is demonstrated in BAALL (www.baall.de), DFKI’s Bremen Ambient Assisted Living Lab, a 60m² apartment fully equipped for trial living of two seniors: sliding doors are opened, light is switched on, the kitchenette/cupboards/microwave is moved to an appropriate height; a higher service such as “reading in bed” adjusts the bed to a comfortable reading position, dims the lights, closes the doors, etc. Uttering an intention such as “I want to eat a pizza” triggers proactive actions in the environment, affecting doors, lights, kitchenette, fridge and corresponding routes. Such services should be extended to building and outdoor environment control, such as remote door and lift controls or activation of traffic lights at street crossings.

Every-day usability particularly regards the design of individualised user interfaces. In general, interaction of the user with the mobility assistants and the intelligent environment shall be multi-modal, using a standard such as the ISO/IEC 24752 Universal Remote Console standard, URC, an open scalable platform for interoperability and personalised – and thus accessible – user interfaces (see OpenURC.org). One generic mode is by pointing to symbols for services or visualised route graphs on the touch screen of a PDA (such as iPhone, iPad). However, visual faculties decline; the number of options and symbols may become hard to manage. Thus an important alternative is spoken dialogue. Although the general case of natural language interaction (initiation of clarification dia­logues, understanding of dialects, adaptation to individual language deficiencies, etc.) is a research issue, interaction in well-designed restricted dialogues is fairly well developed and can be deployed for goal-oriented navigation.

-> Download presentation