Hand-held electrically powered cut-off tool with a kickback mitigation function

A hand-held electrically powered cut-off tool for cutting concrete and stone by a rotatable cutting disc, the cut-off tool comprising an electric motor arranged to be controlled by a control unit via a motor control interface,

• wherein the control unit is arranged to obtain data indicative of an angular velocity of the cutting disc, to process the data indicative of the angular velocity of the cutting disc via a first and second low-pass filter to eliminate excess measurement noise, and to detect a kickback condition based on a decrease in angular velocity,
• wherein the first low-pass filter has a larger bandwidth for kickback condition detection, and the second low-pass filter is applied for normal electric motor control,
• wherein the control unit is arranged to determine an angular acceleration associated with the electric motor, and to detect the kickback condition based on a comparison between the determined angular acceleration and a detection threshold if the angular velocity of the cutting disc is above a velocity threshold.