An automated guided vehicle (AGV) control system which is downward compatible with existing guidewire systems pro-viding both guidewire navigation and communication and autonomous navigation and guidance and wireless communication bet-tween a central controller and each vehicle. Autonomous vehicle navigation comprises travel over paths marked by update mark-ers 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 guid-ance errors caused by such factors as angular rate sensor drift, wear, temperature changes, aging, and early miscalibration during vehicle operation. The control system comprises 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 communications sys-tems.

Passive guidance system

Downward compatible AGV system and methods

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. The vehicle can also navigate by dead reckoning between terminals.

Proportional position-sensing system for an automatic guided vehicle

A system for operating electrically propelled miniature vehicles along a roadbed having side-by-side current conductive lanes with substantially flush tread surfaces and for remotely controlling the vehicles in a manner to turn out and pass one another at the will of the operator as the vehicles are transferred freely from one lane to another. The vehicles are driven by reversible propulsion motors mounted on the vehicle bodies for operating a pair of rear driving wheels connected by a rear axle. The motor rotates a threaded shaft extending fore and aft of the vehicle body, with a nut threaded on the shaft and operatively associated with front steering wheels to turn the steering wheels in opposite directions depending on the fore or aft movement of the nut in response to opposite rotational movement of the threaded shaft. The reversible propulsion motor is operatively connected to the rear axle through gear trains having oppositely oriented one-way clutches so that the rear wheels are driven by the propulsion motor regardless of the direction of operation of the motor.

System for operating miniature vehicles

A guidance system for guiding a plurality of unmanned vehicles along guide wires. A plurality of data communication circuits are provided which form an extensive network. A traffic control computer composes a coded vehicle instruction for assigning tasks and allocates resources to said unmanned vehicles. The traffic control computer polls the status of each vehicle at varying time intervals and receives a response from said vehicle. The network connecting the computer and the communication circuits prevents reception of data transmissions from more than one vehicle at a time. Other messages are temporarily, stored. Data transmitters generate low frequency, low power signals which have a high data transmission rate. Digital data is converted at the transmitters into cosine waveforms of selected frequencies. The cosine waveforms are transposed into sine waveforms at receivers. Low impedance or high impedance characteristics are imposed upon the guide wires. A low frequency, high gain transmit antenna for each vehicle is prorated.

Guide wire communication system and method

An improved magnetic object detecting system having high sensitivity and noise immunity is disclosed. The detection system is of the type having a stimulation coil for generating a magnetic field and a pair of magnetic field detection coils, and the stimulation coil is of a magnetic core type employing a magnetic core.

Passive guidance system

Citations

Downward compatible AGV system and methods

Proportional position-sensing system for an automatic guided vehicle

System for operating miniature vehicles

Guide wire communication system and method

Magnetic object detecting system for automated guided vehicle system

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