Eaton-kenway, Inc.

Hk Systems, Inc.

Gary L Whatcott

James V Yardley

John A Petersen

Bryan A Bloomfield

Herman P Schutten

Vaughn W Guest

Robert K Forman

L Bruce Christensen

Rick S Mottes

Joseph Zuercher

Paul T Carter

Leigh E Sherman

Richard M Dicks

David C Madsen

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. FIGS. 90, 91, 92, 93, and 94 provide a map showing relative orientation of the schematic circuits seen in FIGS. 90A-B, 91A-B, 92A-B, 93A-B, and 94A-B, respectively over paths marked by update markers which may be spaced well apart, such as fifty feet. Redundant measurement capability using 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. 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. The non-linear path originates with an initial direction equal to the heading of the vehicle as it enters the path and a waypoint heading defined as part of the message received from the central control system which plans and controls travel of each vehicle in the system.

Downward compatible AGV system and methods

A low-cost solid state replacement circuit for an inertial platform with the resulting consequence of increased resolution, significantly reduced cost, and improved reliability and accuracy. The invention comprises no moving parts and permits the use of a strap-down angular rate sensor system which has a fixed orientation relative to an AGV on which the circuit is used. The invention creatively emulates encoder signals previously emanating from the inertial table through the use of a voltage controlled oscillator, a direction of turn determining circuit and an encoder emulator. Cabling which exists in current inertial tables does not need to be changed and information format previously used remains unchanged.

Method and apparatus for an AGV inertial table having an angular rate

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. The non-linear path orginates with an initial direction equal to the heading of the vehicle as it enters the path and a waypoint heading defined as part of the message received from the central control system which plans and controls travel of each vehicle in the system.

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. 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 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. The non-linear path comprises an initial direction equal to the heading of the vehicle as it enters the path and a waypoint heading defined as part of the message received from the central control system which plans and controls travel of each vehicle in the system.

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. Such precalibration and averaging provides an improved accuracy of the lateral or first dimensional position measurement between the array of Hall sensors and the magnet. A high frequency measurement of the time at which the signals from the row of sensors reaches a peak value, which is the time that the row of sensors arrives at the magnet, provides an improved second dimensional position measurement. More than one magnet is read concurrently to provide position and bearing information during one processing cycle.

Update marker system for navigation of an automatic guided vehicle

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. Such precalibration and averaging provides an improved accuracy of the lateral or first dimensional position measurement between the array of Hall sensors and the magnet. A high frequency measurement of the time at which the signals from the row of sensors reaches a peak value, which is the time that the row of sensors arrives at the magnet, provides an improved second dimensional position measurement. More than one magnet is read concurrently to provide position and bearing information during one processing cycle.

Update marker system for naviagtion of an automatic guided vehicle

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

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

System for sensing arrival of an automatic guided vehicle at a wire

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

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.

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Holladay, UT, United States of America

Gary L Whatcott