  Guiding robots, in the form of canes or cars, have recently been explored to
assist blind and low vision (BLV) people. Such robots can provide full or
partial autonomy when guiding. However, the pros and cons of different forms
and autonomy for guiding robots remain unknown. We sought to fill this gap. We
designed autonomy-switchable guiding robotic cane and car. We conducted a
controlled lab-study (N=12) and a field study (N=9) on BLV. Results showed that
full autonomy received better walking performance and subjective ratings in the
controlled study, whereas participants used more partial autonomy in the
natural environment as demanding more control. Besides, the car robot has
demonstrated abilities to provide a higher sense of safety and navigation
efficiency compared with the cane robot. Our findings offered empirical
evidence about how the BLV community perceived different machine forms and
autonomy, which can inform the design of assistive robots.
