Microcontroller based voice-activated powered wheelchair control

In social situations, people who use a powered wheelchair must divide their attention between navigating the chair and conversing with people. These conversations could lead to increased mental stress when navigating and distraction from maneuvering the chair. As a solution that maintains a good conversation distance between the wheelchair and the accompanying person (Social Following), a wheelchair control system was developed to provide automated side-by-side following by wirelessly connecting the wheelchair to the person. Two ultrasonic range sensors and three piezoelectric ultrasonic transducers were used to identify the accompanying person and determine their position and heading. Identification involved an ultrasonic beacon worn on the person’s side, at hip level, and receivers on the wheelchair. A drive control algorithm maintained a constant conversation distance along the person’s trajectory. A plug-and-play prototype was developed and connected to a Permobil F5 Corpus wheelchair with a modified Eightfold Technologies SmartChair Remote. Results demonstrated that the system can navigate a wheelchair based on the accompanying person’s trajectory, which is advantageous for users who require hands-free wheelchair control during social activities.

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ALTERNATIVE WHEELCHAIR CONTROL INVOLVING INTENTIONAL MUSCLE CONTRACTIONS

International Journal of Artificial Intelligence Tools ◽

10.1142/s0218213009000226 ◽

2009 ◽

Vol 18 (03) ◽

pp. 439-465 ◽

Cited By ~ 12

Author(s):

TORSTEN FELZER ◽

BRUNO STRAH ◽

RAINER NORDMANN ◽

SEBASTIAN MIGLIETTA

Keyword(s):

Control System ◽

User Interface ◽

Real Life ◽

Sensory Information ◽

Severe Disabilities ◽

Usual Method ◽

Powered Wheelchair ◽

Intelligent Wheelchair ◽

Control Principle ◽

Wheelchair Control

This paper deals with various ways of controlling an electrically powered wheelchair beyond the usual method involving a manual joystick. The main focus is on the newest version of HaWCoS – the "HAnds-free Wheelchair COntrol System" – allowing persons with severe disabilities to reliably navigate a power wheelchair without the need to use the hands. All the user has to do is to produce a sequence of tiny contractions of an arbitrary muscle, e.g., by raising the eyebrow. The working prototype of the system, which has been realized as a stand-alone device, is introduced in detail, together with a closer look at the muscle-based control principle and a brief description of a PC-based simulator. The advantages and the drawbacks of the system are discussed on the basis of a rather simple real-life experiment. The paper also elaborates on possible approaches to improve HaWCoS (by reducing or eliminating its problems) in the future. In addition to a quick software solution and a controller implementation involving supplemental sensory information, planned "improvements" include the development of an "intelligent wheelchair" with HaWCoS being some sort of a prototype for the User Interface component.

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