Patent attributes
An apparatus for use on comprising a vehicle adapted to move across a surface and responsive to an operator. A head assembly connected to a support on the vehicle is adapted to carry a device for engaging the surface. An actuator on the vehicle raises and lowers the head assembly support relative to the surface. A position control responsive to operator input indicates a head position of the device relative to the surface or range of head positions of the device head assembly relative to the surface support. The head position or the range of head positions indicates a distance or range of distances, respectively, between the device and the surface. A controller responsive to the position control selectively actuates the actuator or maintain the device head assembly in the head position or within the range of head positions as indicated by the position control. As a result, a repeatable position or range of positions of the brush head assembly is obtained, the relative engagement between the head assembly and surface is controlled and the treatment of the surface by the head assembly is controlled. Position control may be used in combination with torque control of motors driving brushes for engaging the surface. Position control may also be used in combination with a pressure control measuring the pressure between of the brush head and assembly on the surface.