Sensory stimulation for human guidance in robot walkers: a comparison between haptic and acoustic solutions

We compare two different solutions to guide an older adult along a safe path using a robotic walking assistant (the c-Walker). The two solutions are based on tactile or acoustic stimuli, respectively, and suggest a direction of motion that the user is supposed to take on her own will. We describe the technological basis for the hardware components, and show specialised path following algorithms for each of the two solutions. The paper reports an extensive user validation activity, with a quantitative and qualitative analysis.