Abstract: A beacon navigation system for a vehicle including a plurality of navigation beacons distributed about a premises through which the vehicle is to navigate, and a detector assembly for sensing a beacon and for resolving the azimuthal angle between the beacon and the vehicle. The system further includes an element for defining an optimum azimuthal angle between that beacon and the vehicle, and a device for determining the difference between the resolved angle and the optimum angle to represent the deviation of the vehicle from a designated path. A method of establishing navigational paths among navigation nodes proximate beacons is also disclosed.

Abstract: A position locating system for a vehicle such as a mobile robot which includes a multisector sensor for sensing the coded signal emitted by a beacon. There are means responsive to the sensor for generating a code data signal representative of the coded signal and means responsive to the sensor sectors for generating an angle data signal representative of the angle from sensor to the beacon and at least one of the azimuthal and altitude dimensions.

Abstract: This invention features a mobile robot having a body which has an azimuthal angle that is optimally fixed in space and provides the basic reference for the robot to the outside world. The robot further includes a drive system having wheels for enabling movement of the robot, a synchronous steering mechanism which turns the wheels independently of the body, and a head which turns with the wheels. The robot further includes memory for storing the azimuthal angle of the body, a detector assembly disposed in the head for sensing a navigation beacon and resolving an angular deviation between the head and the beacon, and an element for incrementing the stored azimuthal angle by that angular deviation. A system for enabling orientation adjustment is also disclosed.

Abstract: A recharge docking system for a battery-powered mobile robot which senses when the battery charge is below a predetermined level and halts the travel of the robot at its next navigational node, following which the robot independently plots and negotiates a path from the next node back to a base node at a recharge station, where the batteries are charged.

Abstract: An intrusion detector has a first sensor for monitoring a first condition and a second sensor for monitoring a second condition in a space to be protected against intrusion; a change in the condition sensed by the first sensor in a target area causes the second sensor to be aligned with the same target area; and if both sensors indicate a change in the respective conditions that they monitor an intrusion is indicated.

Abstract: A system for avoiding obstacles in the path of a vehicle including a sensor assembly having a field of view with a plurality of sectors for detecting the distance of objects within each sector. The system further includes an element for identifying obstructed sensors in which objects are detected within a predetermined range and a device for selecting an unobstructed sector close in alignment to the direction of the path to designate around the object a clear path which is close to the original path.

Abstract: A power-up sequencing apparatus for successively energizing a plurality of associated subsystems in a host system, including a series of interconnected sequencing circuits, each sequencing circuit interconnected with a subsystem and including first switching means responsive to an initial system power-up for disabling its associated subsystem; second switching means responsive to an initial system power-up for suppressing the start command to the next sequencing circuit in the series; and third switching means responsive to a start command for operating the first switching means to enable its associated subsystem and for operating the second switching means to introduce a start command to the next sequencing circuit in the series.

Abstract: A proximity detection system for determining the distance between a vehicle and a navigation beacon by resolving the altitude angle between the beacon and the vehicle and determining the distance between them. The system then defines an optimum distance between the beacon and the vehicle and compares the determined distance and the optimum distance to establish any difference between them.

Abstract: An ultrasonic ranging system includes transformer means with a transformer which is selectively energized to produce a transducer drive signal. An ultrasonic transducer transmits an ultrasonic pulse in response to the drive signal and develops an echo signal upon receipt of an echo pulse derived from the ultrasonic pulse; a shunt switch is connected across a winding of the transformer and is selectively closed to quickly damp the ringing following the transmission of an ultrasonic pulse to a level substantially below the level of the echo signal to permit close ranging.