Stacker crane control system

Claim 2

In combination with a load carrier propelled in two transverse directions by reversible change speed drives and displaced by preselected distances in a third direction by displacing mechanism for transfer of loads to and from a plurality of storage racks, a system for programming movement of the load carrier including position signalling means for registering the positions of the load carrier along said two transverse directions, command means for selecting one of the storage racks to which the load carrier is to be propelled, timecontrolled means for intermittantly comparing the position of the load carrier as indicated by the position signalling means with the position of the selected one of the racks relative to said two transverse directions, and means for contrOlling the change speed drives in accordance with the difference in position as indicated by the time-controlled comparing means.

Claim 3

The combination of claim 1 including means responsive to extension of the load carrier in said third direction into the selected one of the racks for displacement of the load carrier by a fixed amount in a vertical one of said two transverse directions.

Claim 4

The combination of claim 2 including a displacing mechanism responsive registration of zero difference by the time-controlled comparing means for displacing the load carrier along said third direction.

Claim 5

The combination of claim 3 wherein said load carrier is propelled in one of said two directions by a vehicle drive motor and in the other of said two directions by an elevator motor, said position signalling means including angle shaft encoders driven by said motors.

Claim 6

The combination of claim 1 including a displacing mechanism responsive registration of zero difference by the time-controlled comparing means for displacing the load carrier along said third direction.

Claim 7

The combination of claim 1 wherein said load carrier is propelled in one of said two directions by a vehicle drive motor and in the other of said two directions by an elevator motor, said position signalling means including angle shaft encoders driven by said motors.

Claim 8

In combination with a vehicle having powered means for movement thereof along predetermined paths between predetermined stations, a system for controlling movement of the vehicle comprising means for sensing position and motion of the vehicle and the condition of the stations, a data processing computer having selectively controlled input command means and interface circuit means interconnecting the computer with the sensing means and the powered means for transmitting address and command data to control movement of the vehicle, said interface circuit means including clock means for periodically initiating a data processing cycle of the computer following receipt of address data from the sensing means, said clock means having a timing cycle greater than the duration of said data processing cycle.

Claim 9

In combination with a vehicle having powered means for movement thereof along predetermined paths between predetermined stations, a system for controlling movement of the vehicle comprising means for sensing position and motion of the vehicle and the condition of the stations, a data processing computer having selectively controlled input command means and interface circuit means interconnecting the computer with the sensing means and the powered means for transmitting address and command data to control movement of the vehicle, said interface circuit means including clock means for periodically initiating a data processing cycle of the computer following receipt of address data from the sensing means, said clock means having a timing cycle greater than the duration of said data processing cycle.

Claim 10

The combination of claim 7 wherein said interface circuit means further includes surveillance means normally receiving a signal pulse during each data processing cycle for disabling the powered means in the absence of timely receipt of the signal pulse.

Claim 11

The combination of claim 8 wherein said sensing means includes angle shaft encoders driven by the powered means.

Claim 12

The combination of claim 9 wherein said powered means includes a change speed drive mechanism for propelling the vehicle at high and low speeds and brake means for stopping movement of the vehicle.

Claim 13

The combination of claim 10 wherein said computer includes subtracting means for determining the difference between data received from the sensing means and data received from the input command means to periodically register the distance between the vehicle and a preselected station, means responsive to a registered distance of zero for generating a brake applying signal, means responsive to a registered distance greater than a predetermined braking constant for generating a high speed signal and means responsive to a registered distance less than the braking constant for generating a low speed signal, said braking applying signal and speed signals being transmitted by the interface circuit means respectively to the brake means and the drive mechanism of the powered means.

Claim 14

The combination of claim 7 wherein said powered means includes a change speed drive mechanism for propelling the vehicle at high and low speeds and brake means for stopping movement of the vehicle.

Claim 15

The combination of claim 12 wherein said computer includes subtracting means for determining the difference between data received from the sensing means and data received from the input command means to periodically register the distance between the vehicle and a preselected statIon, means responsive to a registered distance of zero for generating a brake applying signal, means responsive to a registered distance greater than a predetermined braking constant for generating a high speed signal and means responsive to a registered distance less than the braking constant for generating a low speed signal, said brake applying signal and speed signals being transmitted by the interface circuit means respectively to the brake means and the drive mechanism of the powered means.

Claim 16

In combination with a vehicle having powered means for movement thereof along predetermined paths between predetermined stations, a system for controlling movement of the vehicle comprising means for sensing position of the vehicle, a data processing computer, selectively controlled input command means and interface circuit means interconnecting the computer with the sensing means and the powered means for transmitting data, said computer including subtracting means for determining the difference between data received from the sensing means and data received from the input command means to periodically register the distance between the vehicle and a preselected station, means responsive to a registered distance of zero for generating a brake applying signal, means responsive to a registered distance greater than a predetermined braking constant for generating a high speed signal and means responsive to a registered distance less than the braking constant for generating a low speed signal, said brake applying signal and speed signals being transmitted by the interface circuit means to the powered means.

Claim 17

In combination with a vehicle having powered means for movement thereof along predetermined paths between predetermined stations, a system for controlling movement of the vehicle comprising means for sensing position of the vehicle, a data processing computer, selectively controlled input command means and interface circuit means interconnecting the computer with the sensing means and the powered means for transmitting data, said computer including subtracting means for determining the difference between data received from the sensing means and data received from the input command means to periodically register the distance between the vehicle and a preselected station, means responsive to a registered distance of zero for generating a brake applying signal, means responsive to a registered distance greater than a predetermined braking constant for generating a high speed signal and means responsive to a registered distance less than the braking constant for generating a low speed signal, said brake applying signal and speed signals being transmitted by the interface circuit means to the powered means.

Claim 18

The combination of claim 14 wherein said vehicle includes a load supporting platform and said powered means includes means for propelling the vehicles in a first horizontal direction, elevator means for moving the platform in a second vertical direction and a displacing mechanism for moving the platform in a third horizontal direction by a predetermined amount, and detector means for indicating alignment between the platform and said preselected station to initiate operation of the displacing mechanism.

Claim 19

The combination of claim 15 wherein said computer further includes means for generating a signal in response to said movement of the platform by said predetermined amount to operate the elevator means thereby vertically displacing the platform by a fixed amount.

Claim 20

In combination with a vehicle having an elevator, a carrier mounted on the elevator, propelling means mounted by the vehicle for movement of the carrier along predetermined paths from a starting position, sensing means carried by the vehicle for continuously measuring distance travelled by the carrier from said starting position along said paths, drive control means operatively connected to said propelling means for stopping movement of the carrier at another position preselected by input command data, time-control means for sampling distance measurements of the sensing means at fixedly spaced intervals of time, computer means for comparing each of said sampled measurements with the input command data to produce difference signal outputs and interface means operatively connecting the sensing means and the drive control means to the computer means for transmitting the sampled measurements to the computer means and the outputs from the computer means to the drive control means thereby controlling movement of the carrier in accordance with each of said outputs of the computer means.

Claim 21

In combination with a vehicle having an elevator, a carrier mounted on the elevator, propelling means mounted by the vehicle for movement of the carrier along predetermined paths from a starting position, sensing means carried by the vehicle for continuously measuring distance travelled by the carrier from said starting position along said paths, drive control means operatively connected to said propelling means for stopping movement of the carrier at another position preselected by input command data, time-control means for sampling distance measurements of the sensing means at fixedly spaced intervals of time, computer means for comparing each of said sampled measurements with the input command data to produce difference signal outputs and interface means operatively connecting the sensing means and the drive control means to the computer means for transmitting the sampled measurements to the computer means and the outputs from the computer means to the drive control means thereby controlling movement of the carrier in accordance with each of said outputs of the computer means.

Claim 22

The combination of claim 17, wherein the computer means includes means responsive to successful processing of the sampled measurements and input data for producing a cycle signal at a frequency higher than the frequency of said fixedly spaced intervals of time; and surveillance means responsive to the absence of said cycle signal for disabling the drive control means.

Claim 23

The combination of claim 18, wherein the propelling means includes displacing means for imparting fixed incremental movement to the carrieR prior to movement thereof toward the other preselected position.

Claim 24

The combination of claim 17, wherein the propelling means includes displacing means for imparting fixed incremental movement to the carrier prior to movement thereof toward the other preselected position.