A Study of Chainsaw Kickback

Chainsaw kickback is a serious safety concern for both experienced and novice operators. A key to developing improved
kickback control systems is a better understanding of saw motion during kickback and the development of improved methods
for distinguishing kickback from normal saw operation. In this study, accelerometers and gyroscopes were mounted to a
battery-powered electric chainsaw and to a midsize, gasoline-powered chainsaw, and data were collected during normal
cutting and kickbacks. These sensors measured accelerations along the guide bar and perpendicular to the bar as well as
rotational velocities toward the operator?s torso. Results from the battery-powered saw showed that accelerations during
normal cutting and kickbacks had peak magnitudes of from ;2 to ;6 g and from ;6 to ;8 g, respectively, and that
rotational velocities typically reached over 6008/s during a kickback. Analysis of these results showed that the gyroscope
alone, using a threshold value of 3008/s, was effective in distinguishing normal cutting from kickback. Results from the
gasoline-powered saw showed the same general trends as those with the battery-powered saw; however, the rotational
velocities during a kickback were greater, typically exceeding 1,0008/s. Through the use of machine learning techniques, a
more effective method than a simple threshold for distinguishing kickback from normal saw operation was developed. Using
this method, kickback was determined very reliably and often when the deviations from the rotational velocities
corresponding to normal cutting were small. Implementation of these findings could lead to improved kickback control
systems on chainsaws.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member