US Patent 11691047 Treadmill speed control

A speed control system and method for controlling the speed of an endless belt loop of a treadmill. The speed control system comprises a plurality of image sensors, each image sensor configured to take an image of a user of the treadmill; and a controller configured to control the speed of the endless belt loop by (a) receiving the images of the user taken by the image sensors, (b) rectifying the images based on a calibration of the image sensors, (c) comparing the images to form a disparity map, (d) determining a distance of a user of the treadmill relative to the treadmill using the disparity map, and (e) calculating velocity or acceleration of the treadmill based on the determined distance of the user.