Abstract: An unmanned, self-propelled vehicle in the nature of a mobile robot has an on-board computer that stores path and machine function instructions and activates the drive and steering systems so as to cause the machine to follow a desired path. A plurality of retroreflective targets are mounted along the desired path. They do not have to be mounted at a specific height or distance apart, nor need they be square to the path. An improved guidance system for keeping the vehicle on the prescribed path includes a laterally scanning laser transmitter-receiver mounted on the vehicle. An electromechanical tracking device controls the angle of elevation of the laser beam so as to keep it aimed at each target successively as the vehicle moves. The laser produces signals which steer the vehicle such that the laser transmitter and targets are kept aligned in a vertical plane.

Abstract: A machine configuration which permits readily maneuvering a vehicle away from a wall or line of objects that the vehicle has been traveling close to, or closely following the walls around an inside corner. The vehicle has a frame carrying two rear drive wheels and one or more front caster wheels. The drive wheels are individually driven by separate motors. The drive wheels are inset from the sides of the machine so that turning maneuvers can be made adjacent a wall without the wheels contacting the wall. The rear frame or structure of the machine is disposed within an envelope defined such that turning maneuvers adjacent a wall unit will not bring the rear structure into contact with the wall. With the steering geometry and frame construction set up in this manner, the vehicle can be turned away from the wall by operating the drive motors at differential rates, and no part of the vehicle will touch the wall. The vehicle can also follow closely along an inside corner of two walls.

Abstract: An unmanned, self-propelled vehicle in the nature of a mobile robot has an on-board computer that stores path and machine function instructions and activates the drive and steering systems so as to cause the machine to follow a desired path. A plurality of retroreflective targets are mounted along the desired path. They do not have to be mounted at a specific height or distance apart, nor need they be square to the path. An improved guidance system for keeping the vehicle on the prescribed path includes a laterally scanning laser transmitter-receiver mounted on the vehicle. An electromechanical tracking device controls the angle of elevation of the laser beam so as to keep it aimed at each target successively as the vehicle moves. The laser produces signals which steer the vehicle such that the laser transmitter and targets are kept aligned in a vertical plane.

Abstract: An unmanned, self-propelled vehicle in the nature of a mobile robot has an on-board computer that stores path and machine function instructions and activates the drive and steering systems so as to cause the machine to follow a desired path. A plurality of retroreflectve targets are mounted along the desired path. They do not have to be mounted at a specific height or distance apart, nor need they be square to the path. An improved guidance system for keeping the vehicle on the prescribed path includes a laterally scanning laser transmitter-receiver mounted on the vehicle. An electromechanical tracking device controls the angle of elevation of the laser beam so as to keep it aimed at each target successively as the vehicle moves. The laser produces signals which steer the vehicle such that the laser transmitter and targets are kept aligned in a vertical plane.

Abstract: An automatic tool torque compensator for a surface maintenance machine such as a sweeper or scrubber includes an actuator for raising and lowering one or more rotatable surface maintenance tools and one or more electric or hydraulic motors for driving the tools. There is a circuit for sensing the current load in at least one of the electric motors, or the differential pressure in one or more of the hydraulic motors, and providing a signal representative thereof. There is a circuit for manually selecting a desired tool torque to be applied from a plurality of possible tool torques and for providing an electrical signal representative thereof. The electrical signal representative of the desired tool torque to be applied to the tools and the drive motor load current signal or the differential hydraulic pressure signal representative of actual tool torque applied to the tools are used to control the actuator for raising and lowering the surface maintenance tools.

Abstract: There is disclosed an improvement in a surface maintenance machine whereby means are provided for automatically maintaining a desired normal force by a maintenance tool against a surface being maintained, although there may be undulations in the surface, variations in the condition of the surface and changes in the tool caused by wear. Normal force is applied to the tool by gravity and an actuator, both acting through a load cell which senses their algebraic sum, compares this with a preset desired force and operates the actuator as needed to maintain the force at or near the pre-set level. Further, the load on the motor or motors driving the tool is sensed and compared against high and low reference points. If drive motor load is outside of the reference limits a signal is provided which causes a decrease or increase in the normal force to maintain the motor load within limits.

Abstract: A floor scrubber has rotating brushes for scrubbing a floor, drive motors for the brushes, and a brush height control circuit for raising and lowering the brushes in accordance with a desired brush pattern. The scrubber includes a solution tank, a recovery tank and a detergent tank for application and recovery of the cleaning solution. A solution tank pump, a detergent tank pump and a fan for use in vacuuming used cleaning solution into the recovery tank are each connected to their respective tanks. There are actuating means connected to the brush drive motors, pumps, fan and brush height control circuit. Sensors monitor the solution tank, recovery tank and detergent tank, as well as the speed of the floor scrubber. A start signal for the actuating means is only provided when the sensors determine certain prestart conditions have been met in the solution tank, recovery tank, detergent tank and a certain predetermined speed has been reached for the floor scrubber.

Abstract: .Iadd.A sweeping machine having a frame, a pair of support members, and means for mounting the support members on the frame. A brush is rotatably mounted between the support members. A drive mechanism for the brush includes a source of power in a form capable of being transmitted by conduit means and a motor attached to one of the support members and being located substantially within an interior chamber defined by the brush and with the motor being capable of utilizing power from the source to rotate the brush..Iaddend.