Abstract: An overspeed brake mechanism for a storage and retrieval vehicle (SRV). The brake mechanism includes wedges acting between a brake block attached to the load carriage of the SRV and the mast of the SRV. The wedges are biased into engagement with the mast and are held out of engagement under normal operating conditions by electromagnets which apply an attractive force to the wedges, the electromagnets being de-energized by a control system responsive to an overspeed signal from a tachometer generator on the load carriage and having its input member in engagement with the mast. In accordance with a further aspect of the invention, permanent magnets imbedded in the wedges bias the wedges into light contact with the mast to insure that there will be no lost motion between the wedges and the mast when the brake is activated.

Abstract: An automated guided vehicle (AGV) control system which is downward compatible with existing guidewire systems providing both guidewire navigation and communication and autonomous navigation and guidance and wireless communication between a central controller and each vehicle. Vehicle steering and control includes autonomous guidance and navigation of the vehicle over paths marked by update markers which may be spaced well apart, such as fifty feet. The control system employs high frequency two-way data transmission and reception capability over the guidewires and via wireless communications. The same data rates and message formats are used in both guidewire and wireless communications systems. Substantially the same communications electronics are used for the central controller and each vehicle. Novel navigation and guidance algorithms are used to select and calculate a non-linear path to each next vehicle waypoint when the vehicle is operating in the autonomous mode.

Abstract: A connector assembly for interconnecting a vehicle and a trailer having a hitch element includes a gripper assembly which is operable to engage the hitch element. The gripper assembly includes a plurality of jaws which are pivotally connected with and are disposed in a circular array on a base. A rotatable ring circumscribes the circular array of jaws. A motor is connected with the ring and is operable to rotate the ring in a first direction to pivot the jaws toward each other. The motor is operable to rotate the ring in a second direction, which is opposite to the first direction, to pivot the jaws away from each other. The ring and jaws are interconnected by a plurality of links. The motor is connected with the ring by a drive chain. A hitch element detector detects when the hitch element is positioned in the gripper assembly. A ring position detector detects when the ring is in predetermined positions relative to the base.

Abstract: An automated guided vehicle (AGV) control system which is downward compatible with existing guidewire systems providing both guidewire navigation and communication and autonomous navigation and guidance and wireless communication between a central controller and each vehicle. Autonomous vehicle navigation comprises travel over paths marked by update markers which may be spaced well apart, such as fifty feet Redundant measurement capability comprising inputs from linear travel encoders from the vehicle's drive wheels, position measurements from the update markers, and bearing measurements from a novel angular rate sensing apparatus, in combination with the use of a Kalman filter, allows correction for navigation and guidance errors caused by such factors as angular rate sensor drift, wear, temperature changes, aging, and early miscalibration during vehicle operation.

Abstract: A self-propelled mobile stacker for an automated storage and retrieval system having a mast assembly of lightweight non-metallic material removably installed on a metal chassis. The mast assembly comprises a mast and base formed of a common "I"-shaped composite with the mast secured in the vertical position exclusively by composite non-metallic material gussets adhesively bonded by epoxy to the mast and base.

Abstract: An improved accuracy position and direction updating system for use with an automatic guided vehicle that navigates by dead reckoning. Permanent magnets providing detectable position indicators are mounted in the floor and may be at widely spaced locations such as fifty feet apart along the route of the vehicle. A row of Hall sensors is transversely mounted on the vehicle. The sensors detect the lateral location of each floor magnet relative to the vehicle as the vehicle passes over the magnet. Sensors are precalibrated, correcting for errors in sensor null voltage readings due to changes in sensor characteristics due to causes comprising aging and temperature. Data from five sensors that are closest to the magnet are correlated with a stored pattern of magnetic field and their position data are averaged to determine a first estimate of the lateral or first dimensional position of the vehicle. A running average is calculated from sequentially acquired estimates to improve the results.

Abstract: Novel braking system, assemblies, and methods for storage and retrieval vehicles finding particular application on dual mast storage and retrieval vehicles where it is important to brake both sides of a carriage disposed between the two masts simultaneously. The braking system comprises an actuator assembly which further comprises a tach/generator which derives rotational energy from the rate-of-travel of the carriage relative to an associated guide rail. An electrical circuit, which runs off power derived from the tach/generator, detects overspeed rate-of-travel of the carriage and sends an electrical signal, also deriving power from the tach/generator, to electrically actuate at least one brake. Each brake is firmly affixed to the carriage and comprises a cam which is electrically driven by a solenoid, to engage an associated guide rail when actuated. When the cam is actuated and the carriage falls toward the braking cam, interposed shock absorbers decelerate the carriage.

Abstract: A material handling apparatus is used to sequentially move rolls of material having cores from a loading station to an unwinding station and to sequentially move empty roll cores from the unwinding station. The apparatus includes a generally H-shaped transfer frame having spindle assemblies at opposite ends of the transfer frame. When spindle assemblies at one end of the frame have engaged the core of a first roll at the loading station, the frame is pivoted about the central axes of the spindle assemblies while the first roll remains stationary at the loading station. This pivotal movement moves an empty core along an arcuate path from the unwinding station to a position above the stationary first roll at the loading station. The first roll is then moved from the loading station to the unwinding station. The spindle assemblies have wheels which roll along rails during movement of the first roll from the loading station to the unwinding station.

Abstract: An improved accuracy position and direction updating system for use with an automatic guided vehicle that navigates by dead reckoning. Permanent magnets providing detectable position indicators are mounted in the floor and may be at widely spaced locations such as fifty feet apart along the route of the vehicle. A row of Hall sensors is transversely mounted on the vehicle. The sensors detect the lateral location of each floor magnet relative to the vehicle as the vehicle passes over the magnet. Sensors are precalibrated, correcting for errors in sensor null voltage readings due to changes in sensor characteristics due to causes comprising aging and temperature. Data from five sensors that are closest to the magnet are correlated with a stored pattern of magnetic field and their position data are averaged to determined a first estimate of the lateral or first dimensional position of the vehicle. A running average is calculated from sequentially acquired estimates to improve the results.

Abstract: Apparatus for detecting and controlling the position of an automatic guided vehicle to enable precise positioning of the vehicle at a predetermined place such as a load pickup/delivery terminal. In one embodiment a mat having a passive short-circuited loop of wire embedded in it is positioned on the floor at the terminal. On the vehicle an oscillator and a transmitting antenna provide a primary magnetic field that excited the loop in the mat whenever the vehicle is in the terminal, inducing current in the loop. The current in the loop produces a secondary magnetic field having a predetermined spatial pattern. Receiving antennas on the vehicle detect the secondary magnetic field. Prior knowledge of the spatial pattern enables onboard electronic apparatus to ascertain the position of the vehicle relative to the mat. Both transverse and longitudinal position can be detected and controlled. The same on-board apparatus enables the vehicle to follow an energized guidewire in the floor between terminals.

Abstract: Traction apparatus for driving a vehicle and accurately sensing the distance traveled, in which a drive mechanism is encircled by a separate ring-shaped encoder wheel. The encoder wheel, which is part of a travel-sensing mechanism, nests annularly with the drive mechanism so that the width of the combination is minimized. The travel-sensing mechanism can be assembled to the vehicle without disturbing the drive mechanism. There is enough radial clearance in the toroidal encoder wheel to permit the drive mechanism to move up and down within the encoder wheel. The encoder wheel has approximately the same outside diameter as the drive wheel, so certain common-mode measurement errors cancel. The encoder wheel and the drive wheel are approximately concentric and closely spaced laterally to minimize measurement errors that would otherwise occur upon turning of the vehicle.

Abstract: A novel trailer towing apparatus for an AGV whereby downwardly applied, vertically oriented towing loads are substantially, directly imposed upon the drive wheels of the AGV, thereby increasing wheel to ground frictional forces and resulting towed load capacity. The towing apparatus is attached to the top of the AGV thereby allowing the AGV to turn through a 360.degree. radius without moving the trailer.

Abstract: A load rotator assembly rotates and positions loads which are transferred between vehicles which move along aisles. The load rotator assembly includes a carriage which sequentially receives loads from one of the vehicles. A carriage drive assembly rotates the carriage about a vertical axis while maintaining the load on the carriage offset to one side of a vertical plane through the ends of loads at storage locations to eliminate any possibility of interference between the load and a stacker crane which transfers the load to one of the storage locations. The carriage drive assembly is operable to move the carriage toward the vertical plane. By positioning a load on the carriage with its end in the vertical plane, the stacker crane can pick up the load from the carriage and move the load to a storage location. The carriage drive assembly includes a double geneva drive mechanism having upper and lower geneva plates.

Abstract: A novel vertical drive assembly for a storage and retrieval vehicle wherein a cable drive motor is horizontally juxtaposed between a lift cable winding and unwinding drum. The vertical drive assembly is modularly assembled on a frame and is attachable and detachable from the vehicle as a unit. The vertical drive assembly comprises, in seriatim, the motor, a belt drive sprocket wheel, a drive belt, a belt driven sprocket wheel, and, juxtaposed and on the same axis as the driven sprocket wheel, an input adapter, a speed reducer, and the drum. The motor is attached to the frame by jacks used to raise and lower the motor to adjust tension in the belt. To stay within the width of the vehicle, the input adapter and speed reducer are at least partly disposed within the core of the drum with the speed reducer providing a bearing for the drum. To reduce starting inertia, sprocket wheels are fabricated from lightweight material.

Abstract: A novel dual mast storage and retrieval vehicle comprising structure which maintains each mast essentially vertical as variably weighted heavy loads are placed on a carriage disposed between the masts. Each mast is disposed near the center of a separately supported base such that bending of the base under such loads induces little off-vertical deflection to the mast. The separately supported bases are coupled by a connector which comprises cross-aisle and vertical degrees of freedom but is strictly constrained in the down-aisle direction. In the currently preferred embodiment, two down-aisle drive motors, in master/slave relationship, provide a synchronous drive for the vehicle. Further, interconnecting joints a strut at the top of the masts and of the carriage comprise hinges which resist propagation of mast induced moments caused by beam deflection or vehicle dynamics.

Abstract: Apparatus for detecting an automatic guided vehicle's longitudinal position and to enable positioning of the vehicle at a load pickup/delivery terminal or other place. In one arrangement a mat having a passive short-circuited loop of wire embedded in it is positioned on the floor. On the vehicle an oscillator and a transmitting antenna provide a primary magnetic field that excites the loop in the mat, inducing current in the loop. The loop current produces a secondary magnetic field. Magnetic receiving antennas on the vehicle detect the secondary magnetic field that is caused by portions of the loop that cross the longitudinal axis of the vehicle. Onboard electronic apparatus ascertains and can control the longitudinal position of the vehicle relative to the mat. The same on-board apparatus enables the vehicle to detect a directly energized (connected to a power source) guidewire in the floor that lies across the vehicle's path between terminals and at terminals.

Abstract: A novel trailer towing apparatus for an AGV whereby downwardly applied, vertically oriented towing loads are substantially, directly imposed upon the drive wheels of the AGV, thereby increasing wheel to ground frictional forces and resulting towed load capacity. The towing apparatus is attached to the top of the AGV thereby allowing the AGV to turn through a 360.degree. radius without moving the trailer.

Abstract: A mast to base connection for a storage and retrieval machine which incorporates a pin connection between the mast and the base. The base of the machine is formed as a plurality of elongated plates standing on edge with upwardly extending lugs formed integrally with the plates. The mast has similar lugs formed at its lower end which interleave with the lugs on the base. The mast and base are factory prealigned prior to shipment and line bored to receive connecting pins which can be precisely matched to each bore. The invention includes a method by which the mast is assembled to the base at a job site by laying the mast down on the base and inserting one of the connecting pins into the lugs, and then tilting the mast about the pin until the remaining lugs are aligned for insertion of a second pin.

Abstract: A wheel mounting assembly for a rail-supported storage/retrieval machine. The drive and idler wheels are each mounted on a removable module which includes a fixed plate having a concave spherical surface formed in it and movable plate to which the wheel is mounted having a convex spherical surface interfitting with the concave surface on the fixed plate to define a spherical joint. The plates are interconnected by bolts fitting loosely in oversize holes formed in the fixed plate and threaded into the movable plate to provide limited relative movement of the plates about a plurality of axes. Four jackscrews arranged in pairs on opposite sides of the movable plate are threaded through a frame holding the first plate and bear against the sides of the second plate. Simultaneous tightening and loosening among combinations of the four jackscrews provides horizontal and vertical alignment of the wheel relative to the rail on which the machine is supported.

Abstract: An overtravel brake system for a storage and retrieval system which is automatically actuated when the load carriage lift motor is deenergized and the load carriage moves downward. The brake system includes a dog mounted on the load carriage and engageable with the mast, the dog being actuated by a chain or cable which applies an actuating force to the dog actuating mechanism only after the load carriage has traveled a predetermined distance. The chain or cable is connected to the output member of a clutch mechanism operable in response to relative movement between the load carriage and the mast, and which is held in a disengaged condition when the lift motor is energized and is automatically shifted to an engaged condition when the lift motor is deenergized.