Automated bot transfer arm drive system

1. An autonomous transport vehicle comprising:

a transfer arm including at least one finger and a movable finger support member, the at least one finger being movably coupled to the finger support member so that the finger support member moves in a first direction relative to a reference frame of the vehicle and the at least one finger linearly moves relative to the finger support member in a second direction substantially perpendicular to both the first direction in the reference frame of the vehicle and a travel surface on which the autonomous transport vehicle travels;

at least one sensor configured to detect movement of the at least one finger and being indexed to define more than two positions of the at least one finger in the second direction relative to the movable finger support member, the at least one sensor having a registration member and a detection member where one of the registration member and detection member is mounted to each of the at least one finger so as to be linearly movable with and by movement of a respective one of the at least one finger and the other one of the registration member and detection member is stationary relative to the at least one finger; and

a controller in communication with the at least one sensor, the controller being configured to determine a position of the at least one finger, the second direction relative to the movable finger support member, based on a proximity of the registration member relative to the detection member that detects the more than two positions of the at least one finger.

2. The autonomous transport vehicle of claim 1 , wherein the other one of the registration member and detection member is mounted on the movable finger support.

3. The autonomous transport vehicle of claim 1 , wherein the at least one sensor is an optical, capacitive or inductive sensor.

4. The autonomous transport vehicle of claim 1 , wherein the registration member comprises a reflective flag or a magnetic source.

5. The autonomous transport vehicle of claim 1 , wherein the autonomous transport vehicle includes a drive unit for each of the at least one finger, where the controller is configured to actuate the drive unit for each of the at least one finger so each of the at least one finger are moved along the second direction substantially in unison.

6. The autonomous transport vehicle of claim 1 , wherein the drive unit for each of the at least one finger includes a stepper motor.

7. The autonomous transport vehicle of claim 1 , wherein the autonomous transport vehicle includes an inertial sensor coupled to the controller, the inertial sensor being configured to detect a tilt of the autonomous transport vehicle relative to a horizontal plane.

8. An autonomous transport vehicle comprising:

a transfer arm including at least one finger and a movable finger support member, the at least one finger being movably coupled to the finger support member so that the finger support member moves in a first direction and the at least one finger moves relative to the finger support member in a second direction substantially perpendicular to the first direction;

at least one sensor configured to detect movement of the at least one finger, the at least one sensor having a registration member and a detection member where one of the registration member and detection member is mounted to each of the at least one finger so as to be movable with a respective one of the at least one finger and the other one of the registration member and detection member is stationary relative to the at least one finger; and

a controller in communication with the at least one sensor, the controller being configured to determine a position of the at least one finger along the second direction based on a proximity of the registration member relative to the detection member;

wherein the controller is configured to selectively move each of the at least one finger along the second direction depending on a size of a pickface carried by the autonomous transport vehicle.

9. An autonomous transport vehicle comprising:

a transfer arm including at least one finger and a movable finger support member, the at least one finger being movably coupled to the finger support member so that the finger support member moves in a first direction and the at least one finger linearly moves relative to the finger support member in a second direction substantially perpendicular to both the first direction and a travel surface on which the autonomous transport vehicle travels;

at least one sensor configured to detect movement of the at least one finger and being indexed to define more than two positions of the at least one finger, the at least one sensor having a registration member and a detection member where one of the registration member and detection member is mounted to each of the at least one finger so as to be linearly movable with and by movement of a respective one of the at least one finger and the other one of the registration member and detection member is stationary relative to the at least one finger; and

a controller in communication with the at least one sensor, the controller being configured to determine a position of the at least one finger, along the second direction, based on a proximity of the registration member relative to the detection member that detects the more than two positions of the at least one finger;

wherein the other one of the registration member and detection member is mounted on the movable finger support.

10. The autonomous transport vehicle of claim 9 , wherein the at least one sensor is an optical, capacitive or inductive sensor.

11. The autonomous transport vehicle of claim 9 , wherein the registration member comprises a reflective flag or a magnetic source.

12. The autonomous transport vehicle of claim 9 , wherein the autonomous transport vehicle includes a drive unit for each of the at least one finger, where the controller is configured to actuate the drive unit for each of the at least one finger so each of the at least one finger are moved along the second direction substantially in unison.

13. The autonomous transport vehicle of claim 9 , wherein the controller is configured to selectively move each of the at least one finger along the second direction depending on a size of a pickface carried by the autonomous transport vehicle.

14. The autonomous transport vehicle of claim 9 , wherein the autonomous transport vehicle includes an inertial sensor coupled to the controller, the inertial sensor being configured to detect a tilt of the autonomous transport vehicle relative to a horizontal plane.

15. An autonomous transport vehicle comprising:

a transfer arm including at least one finger and a movable finger support member, the at least one finger being movably coupled to the finger support member so that the finger support member moves in a first direction and the at least one finger moves relative to the finger support member in a second direction substantially perpendicular to the first direction;

at least one sensor configured to detect movement of the at least one finger, the at least one sensor having a registration member and a detection member where one of the registration member and detection member is mounted to each of the at least one finger so as to be movable with a respective one of the at least one finger and the other one of the registration member and detection member is stationary relative to the at least one finger; and

a controller in communication with the at least one sensor, the controller being configured to determine a position of the at least one finger along the second direction based on a proximity of the registration member relative to the detection member;

wherein the controller is configured to selectively move each of the at least one finger along the second direction depending on a size of a pickface carried by the autonomous transport vehicle.

16. The autonomous transport vehicle of claim 15 , wherein the other one of the registration member and detection member is mounted on the movable finger support.

17. The autonomous transport vehicle of claim 15 , wherein the at least one sensor is an optical, capacitive or inductive sensor.

18. The autonomous transport vehicle of claim 15 , wherein the registration member comprises a reflective flag or a magnetic source.

19. The autonomous transport vehicle of claim 15 , wherein the autonomous transport vehicle includes a drive unit for each of the at least one finger, where the controller is configured to actuate the drive unit for each of the at least one finger so each of the at least one finger are moved along the second direction substantially in unison.

20. The autonomous transport vehicle of claim 15 , wherein the autonomous transport vehicle includes an inertial sensor coupled to the controller, the inertial sensor being configured to detect a tilt of the autonomous transport vehicle relative to a horizontal plane.