AGV position and heading controller
First Claim
1. A method of controlling an automatic guided vehicle (AGV) comprising:
- measuring the AGV'"'"'s heading;
measuring the AGV'"'"'s location;
determining any error between the AGV'"'"'s measured heading and a desired heading;
determining any error between the AGV'"'"'s measured location and a desired location; and
steering said AGV to simultaneously attempt to reduce said error between the AGV'"'"'s measured heading and desired heading and said error between the AGV'"'"'s measured location and a desired location, including reducing said error between the AGV'"'"'s measured heading and desired headings substantially independently of reducing said error between the AGV'"'"'s measured location and desired location.
3 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for controlling the steering of an automatic guided vehicle (AGV) includes simultaneously correcting the vehicle'"'"'s heading and position errors. The vehicle may include first and second steering control loops that determine the vehicle'"'"'s position and heading errors, respectively. Separate commands are generated from these control loops to steer the vehicle in a manner that tends to reduce these errors. The vehicle may include a forward and a rearward pair of wheels. For correcting position errors, the first control loop issues the same steering command to both the forward and rearward pair of wheels. For correcting heading errors, the second control loop issues a steering command to the rearward pair of wheels that is summed together with the first control loop'"'"'s steering command prior to being applied to the rearward pair of wheels.
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Citations
26 Claims
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1. A method of controlling an automatic guided vehicle (AGV) comprising:
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measuring the AGV'"'"'s heading;
measuring the AGV'"'"'s location;
determining any error between the AGV'"'"'s measured heading and a desired heading;
determining any error between the AGV'"'"'s measured location and a desired location; and
steering said AGV to simultaneously attempt to reduce said error between the AGV'"'"'s measured heading and desired heading and said error between the AGV'"'"'s measured location and a desired location, including reducing said error between the AGV'"'"'s measured heading and desired headings substantially independently of reducing said error between the AGV'"'"'s measured location and desired location. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of controlling an automatic guided vehicle (AGV) comprising:
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measuring the AGV'"'"'s heading;
measuring the AGV'"'"'s location;
determining any error between the AGV'"'"'s measured heading and a desired heading;
determining any error between the AGV'"'"'s measured location and a desired location;
steering said AGV to simultaneously attempt to reduce said error between the AGV'"'"'s measured heeding and desired heading and said error between the AGV'"'"'s measured location and a desired location;
providing at least two first steerable wheels and at least two second steerable wheels on said AGV, said first two wheels being spaced apart longitudinally from said second two wheels;
generating a first steering signal adapted to reduce any difference between the AGV'"'"'s desired position and its measured position;
generating a second steering signal adapted to reduce any difference between the AGV'"'"'s desired heading and its measured heading;
applying said first steering signal to said first two steerable wheels;
adding said first and said second signals together to create an added steering signal; and
applying said added steering signal to said second two steerable wheels. - View Dependent Claims (11, 12)
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13. A method of controlling an automatic guided vehicle (AGV) comprising:
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measuring the AGV'"'"'s heading;
measuring the AGV'"'"'s location;
providing a first control loop that generates a first steering command based upon any difference between said measured AGV position and a desired AGV position;
providing a second control loop that generates a second steering command based upon any difference between said measured AGV heading and a desired AGV heading;
providing at least a first and a second steerable wheel on said AGV, said first and second steerable wheels being spaced apart longitudinally;
applying said first steering command to said first steerable wheel;
adding said first and second steering commands together; and
applying the added together first and second steering commands to said second steerable wheel. - View Dependent Claims (14, 15, 16)
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17. A method of controlling an automatic guided vehicle (AGV) comprising:
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measuring the AGV'"'"'s heading;
measuring the AGV'"'"'s location;
providing a first control loop that generates a first steering command based upon any difference between said measured AGV position and a desired AGV position;
providing a first control loop that generates a second steering command based upon any difference between said measured AGV heading and a desired AGV heading;
providing at least a first and a second steerable wheel on said AGV, said first and second steerable wheels being spaced apart longitudinally;
determining whether said first steerable wheel is a leading or trailing wheel;
determining whether said second steerable wheel is a leading or trailing wheel;
applying said first steering command to the leading wheel;
adding said first and second steering commands together; and
applying the added together first and second steering commands to the trailing wheel.
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18. A method of controlling an automatic guided vehicle (AGV) comprising:
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providing a guidepath;
measuring the AGV'"'"'s position;
determining a closest point on the guidepath for the AGV;
comparing the AGV'"'"'s measured position to the closest point on the guidepath for the AGV; and
generating a steering command for the AGV based upon any difference between the measured position of the AGV and the closest point on the guidepath of the AGV, said steering command causing the AGV to reduce any difference between the AGV'"'"'s measured position and the closest point on the guidepath of the AGV without substantially altering the AGV'"'"'s heading as the AGV moves. - View Dependent Claims (19, 20)
providing a first and a second set of steerable wheels on the AGV, said first and second sets of wheels being spaced apart longitudinally; and
applying said steering command to both said first and said second sets of steerable wheels.
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20. The method of claim 18, further comprising:
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measuring the AGV'"'"'s heading;
determining a desired heading for the AGV;
comparing the AGV'"'"'s measured heading to the desired heading for the AGV; and
generating a second steering command for the AGV based upon any difference between the measured heading of the AGV and the desired heading of the AGV, said second steering command causing the AGV to reduce any difference between the AGV'"'"'s measured heading and the desired heading.
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21. A method of controlling an automatic guided vehicle (AGV) comprising:
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measuring the AGV'"'"'s position;
determining a desired position for the AGV;
comparing the AGV'"'"'s measured position to the desired position for the AGV; and
generating a steering command for the AGV based upon any difference between the measured position of the AGV and the desired position of the AGV, said steering command causing the AGV to reduce any difference between the AGV'"'"'s measured position and the AGV'"'"'s desired position without altering the AGV'"'"'s orientation as the AGV moves;
providing a first and a second set of steerable wheels on the AGV, said first and second sets of wheels being spaced apart longitudinally;
applying said steering command to both said first and said second sets of steerable wheels; and
applying said second steering command to said second set of steerable wheels. - View Dependent Claims (22)
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23. An apparatus for controlling an automatic guided vehicle (AGV) comprising:
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a first controller, said first controller determining any difference between the vehicle'"'"'s measured position and a desired position, said first controller adapted to output a first command that tends to reduce any said difference;
a second controller, said second controller determining any difference between the vehicle'"'"'s measured heading, said second controller adapted to output a second command that tends to reduce any said difference between the measured and desired heading;
at least a first and second steerable wheel, said first and second steerable wheels being spaced apart longitudinally on the AGV; and
wherein said first command is applied to said first steerable wheel and said second command is not applied to said first steerable wheel. - View Dependent Claims (24)
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25. An apparatus for controlling an automatic guided vehicle (AGV) comprising:
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a first controller, said first controller determining any difference between the vehicle'"'"'s measured position and a desired position, said first controller adapted to output a first command that tends to reduce any said difference;
a second controller, said second controller determining any difference between the vehicle'"'"'s measured heading and a desired heading, said second controller adapted to output a second command that tends to reduce an said difference between the measured and desired heading; and
a first set and a second set of steerable wheels, said first set of wheels being spaced apart longitudinally from said second set of wheels on the AGV, wherein said first command is applied to said first set of wheels and said second command is not applied to said first set of wheels. - View Dependent Claims (26)
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Specification