Patent US3873902A successfully refreshed from Google Patents.
US3873902A
Expired / Lapsed
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Positioning control system for material handling vehicles
Assignee: Doosan Bobcat North America Inc
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Filing: 1970-06-15
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Granted: 1975-03-25
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Expires: 1990-06-15
Abstract
Abstract A control system is disclosed for automatically positioning a material handling vehicle at an assigned station with a high degree of positional accuracy. The automatic control system is adapted for an automatic warehouse in which a stacker vehicle is movable in one or more aisles between arrays of storage bins. The automatic control means utilizes address signal devices at each station and a transducer on the vehicle coacting therewith to produce control signals for regulating the movement of the vehicle. The vehicle is moved from one station to another at relatively high speeds which may be reduced as the destination station is approached. When the vehicle arrives at the station, control of the drive motor is transferred to a fine positioning system adapted to drive the vehicle at very low speeds to a reference or null position. In the fine positioning mode of operation a signal device at the station defines first and second limit positions and the transducer includes sensing means with first and second spaced sensors. When both limit positions are detected by the sensors simultaneously the null position is thereby signified and the vehicle is stopped. Additionally, control means are provided to reverse the energization of the drive motor in case the vehicle overshoots the null position. Preferably, the null sensors take the form of proximity detectors using magnets and reed switches and the null signal device takes the form of at least one vane of magnetic material with the ends thereof defining the limit positions.
Inventors
- 👤 Arthur R Burch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:50
CPC Classifications
B; B65; B65G; B65G1/00; B65G1/02; B65G1/04; B65G1/0407; B65G1/0421
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
245 words
A vehicle control system adapted to control the movement of a vehicle into a predetermined position relative to a selected station comprising: motive power means on the vehicle for moving it forward and backward on a path extending past the station, first control means responsive to a destination station command signal for causing energization of the motive power means to move the vehicle in the direction of the selected station at a controlled speed, transition control means responsive to the arrival of the vehicle at the selected station for transferring control of the motive power means from the first control means to a second control means, said second control means including a signal device at the selected station and defining first and second limit positions in the forward and backward directions, sensing means including first and second spaced sensors on the vehicle and adapted to coact with the signal device to produced a binary signal when aligned with either the first or second limit positions of said signal device, said transition control means being connected with said sensing means and responsive to the occurrence of a binary signal from one of said sensors to cause energization of the motive power means for continued movement in the same direction, and a null responsive means connected with said sensing means and responsive to the simultaneous occurrence of binary signals from both of said sensors to interrupt the power to said motive power means and stop said vehicle.
Claim 2
Dependent Claim
245 words
A vehicle control system adapted to control the movement of a vehicle into a predetermined position relative to a selected station comprising: motive power means on the vehicle for moving it forward and backward on a path extending past the station, first control means responsive to a destination station command signal for causing energization of the motive power means to move the vehicle in the direction of the selected station at a controlled speed, transition control means responsive to the arrival of the vehicle at the selected station for transferring control of the motive power means from the first control means to a second control means, said second control means including a signal device at the selected station and defining first and second limit positions in the forward and backward directions, sensing means including first and second spaced sensors on the vehicle and adapted to coact with the signal device to produced a binary signal when aligned with either the first or second limit positions of said signal device, said transition control means being connected with said sensing means and responsive to the occurrence of a binary signal from one of said sensors to cause energization of the motive power means for continued movement in the same direction, and a null responsive means connected with said sensing means and responsive to the simultaneous occurrence of binary signals from both of said sensors to interrupt the power to said motive power means and stop said vehicle.
Claim 3
Dependent Claim
100 words
The invention as defined in claim 1 wherein said motive power means includes a servo amplifier and a motor energized in accordance with the output of the amplifier, said servo amplifier being adapted to be operated in an on-off mode in response to a binary input signal, said second control means connected weith the servo amplifier and being adapted to produce a first binary signal when only one sensor is aligned with either the first or second limit positions and being adapted to produce a second binary signal when both sensors are aligned with said first and second limit positions.
Claim 4
Dependent Claim
62 words
The invention as defined in claim 2 and further including reversing control means connected with said sensing means and with said transition control means and being responsive to the second occurrence of a binary signal from said one of said sensors to reverse the energization of the motive power means to move the vehicle in the other direction toward the predetermined position.
Claim 5
Dependent Claim
96 words
The invention as defined in claim 1 wherein each sensor is adapted to produce a first and second signal when disposed outside and inside of said first and second limit positions respectively, the transition control means being adapted to energize the motive power means in one direction in response to a second signal from one sensor and in the other direction in response to a second signal from the other sensor, said null responsive means being responsive to the simultaneous occurrence of said first signals from both sensors to interrupt the power and stop the vehicle.
Claim 6
Dependent Claim
109 words
The invention as defined in claim 1 wherein said motive power means includes a servo amplifier and a motor energized in accordance with the output of the amplifier, said servo amplifier being adapted to be operated in an on-off mode in response to a binary input signal, said null responsive means including a null responsive circuit adapted to produce a first binary signal when a sensor is within the first and second limit positions and being adapted to produce a second binary signal when the first and second sensors are aligned with said first and second limit positions respectively, said null responsive circuit being connected with said servo amplifier.
Claim 7
Dependent Claim
61 words
The invention as defined in claim 1 wherein said transition control means includes a strobe signal element in said signal device and a strobe sensor in said sensing means adapted to enable the transition control means so long as the strobe sensor is disposed adjacent the strobe signal element and thereby establish the region of control by said second control means.
Claim 8
Dependent Claim
38 words
The invention as defined in claim 6 and further including station address means at said destination station, said sensing means being adapted to read said address means when the strobe sensor is disposed adjacent the strobe signal element.
Claim 9
Dependent Claim
34 words
The invention as defined in claim 7 wherein said region of control by the second control means is determined by the length of the strobe signal element in said direction of the selected station.
Claim 10
Dependent Claim
52 words
The invention as defined in claim 8 wherein the strobe sensor comprises a magnetic field producing means and a magnetic field responsive means with an air gap therebetween and said strobe signal element comprises a plate of magnetic material adapted to extend into said air gap when disposed adjacent said strobe sensor.
Claim 11
Dependent Claim
307 words
A vehicle control system adapted to control the movement of a vehicle into a predetermined position relative to a selected station comprising: motive power means on the vehicle for moving it forward and backward on a path extending past the station, said motive power means including a servo amplifier and a motor energized in accordance with the output of the amplifier, said servo amplifier being adapted to be operated in an on-off mode in response to a binary input signal, first control means responsive to a destination station command signal and adapted to produce a binary input signal of one value to cause energization of the motive power means to move the vehicle in the direction of the selected station at a first speed, transition control means responsive to the arrival of the vehicle at the selected station for transferring control of the motive power means from the first control means to a second control means, the said second control means including a signal device at the selected station and defining first and second limit positions in the forward and backward directions, sensing means including first and second spaced sensors on the vehicle and adapted to coact with the signal device to produce a signal when aligned with either the first or second limit positions of said signal device, said transition control means being connected with said sensing means and responsive to the occurrence of a signal from one of said sensors to produce a binary input signal of a second value to cause energization of the motive power means for continued movement in the same direction at a second speed, and a null responsive means connected with said sensing means and responsive to the simultaneous occurrence of signals from both of said sensors to interrupt the power to said motive power means and stop said vehicle.
Claim 12
Dependent Claim
307 words
A vehicle control system adapted to control the movement of a vehicle into a predetermined position relative to a selected station comprising: motive power means on the vehicle for moving it forward and backward on a path extending past the station, said motive power means including a servo amplifier and a motor energized in accordance with the output of the amplifier, said servo amplifier being adapted to be operated in an on-off mode in response to a binary input signal, first control means responsive to a destination station command signal and adapted to produce a binary input signal of one value to cause energization of the motive power means to move the vehicle in the direction of the selected station at a first speed, transition control means responsive to the arrival of the vehicle at the selected station for transferring control of the motive power means from the first control means to a second control means, the said second control means including a signal device at the selected station and defining first and second limit positions in the forward and backward directions, sensing means including first and second spaced sensors on the vehicle and adapted to coact with the signal device to produce a signal when aligned with either the first or second limit positions of said signal device, said transition control means being connected with said sensing means and responsive to the occurrence of a signal from one of said sensors to produce a binary input signal of a second value to cause energization of the motive power means for continued movement in the same direction at a second speed, and a null responsive means connected with said sensing means and responsive to the simultaneous occurrence of signals from both of said sensors to interrupt the power to said motive power means and stop said vehicle.
Claim 13
Dependent Claim
71 words
The invention as defined in claim 6 wherein said null responsive circuit in said second control means includes means to produce a first binary signal when a sensor is within the first and second limit positions and being adapted to produce a second binary signal when the first and second sensors are aligned with said first and second limit positions respectively, said null responsive circuit being connected with said servo amplifier.
Claim 14
Dependent Claim
106 words
The invention as defined in claim 6 wherein each sensor is adapted to produce a first and second signal when disposed outside and inside of said first and second limit positions respectively, and further including reversinG control means connected with said sensors, the reversing control means being adapted to energize the motive power means in one direction in response to a second signal from one sensor and in the other direction in response to a second signal from the other sensor, said null responsive means being responsive to the simultaneous occurrence of said first signals from both sensors to interrupt the power and stop the vehicle.
References Cited (Backward Citations)
US3407905A
Cited
US3507360A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |