Human and machine stick balancing

We compared the similarities and differences in stick balancing for the human fingertip and that by a servo-controlled machine. The motion of the stick in both cases exhibited a swinging or hunting behavior, which appears to be related to feedback delay. However, human stick balancing appears also to be affected by psychological factors, such as attention, which are not present in machine control systems. We discuss how machine control systems compare with human stick balancing. We also discuss about the repulsive delayed random walk as a simplified model of the stick balancing.