Evaluation of proportional and discrete shared control paradigms for low resolution user inputs

For people with severe physical disabilities, low resolution input devices, such as buttons, sip and puff switches and brain-computer interfaces provide an opportunity to interact with the world. However, it can be difficult to control assistive technology, such as wheelchairs, tele-presence robots and robotic arms, when you have only a limited number of commands available and/or a lack of temporal precision in issuing such commands. These limitations can be overcome by employing shared control techniques, whereby the system assists the user in performing the desired task. In this study we compare the use of a simple discrete shared control policy with a more dynamic proportional shared control policy. We evaluate both approaches on a wheelchair that is only operated by two temporally-constrained discrete buttons. The experiments were performed in two different realistic indoor scenarios: an open-plan, spacious environment and a smaller, more cluttered office environment. A total of 10 healthy participants took part in this study.