Sensor-based Dynamic Control of the Central Pattern Generator for Locomotion

The authors study the dynamic control of ongoing locomotor patterns through the application of discrete pulses of electrical stimulation to the central pattern generator (CPG) for locomotion. Data is presented from a hardware model of the CPG demonstrating that stimulation causes brief deviations from the CPG\´s limit cycle activity. It has been shown that the characteristics of the deviation depend strongly on the phase of stimulation. This paper expands upon those previous results in two ways. Firstly, we provide a more detailed characterization of the limit cycle oscillators (LCOs) with the intent of resolving possible asymmetries. Secondly, we use sensory information from a biped robot\´s "limbs" to set the appropriate timing for the discrete pulse to correct the asymmetries, making it possible to take the computer out of the loop in the generation of the stimulus. Eventually, the authors believe this approach could lead to development of a neuroprosthetic device for restoring locomotion after paralysis or amputation.