Strapping machine strap-feeding assembly for reducing drive-roller slippage

1 . A strapping machine comprising:

a frame;

a load supporter supported by the frame and comprising a support surface;

a strap chute circumscribing the support surface of the load supporter;

a drive roller;

an actuator operably connected to the drive roller to drive the drive roller;

a rotatable pinch roller that forms a nip with the drive roller sized to receive strap therethrough;

a drive-roller sensor configured to sense a drive-roller parameter of the drive roller;

a pinch-roller sensor configured to sense a pinch-roller parameter of the pinch roller;

a controller operably connected to the actuator and communicatively connected to the drive-roller and pinch-roller sensors, wherein the controller is configured to:

during a strap-feeding cycle, control the actuator in accordance with one or more actuator control instructions to drive the drive roller to feed the strap around the strap chute;

determine a drive-roller rotational property of the drive roller based on one or more drive-roller rotational parameters sensed while the strap is being fed around the strap chute;

determine a pinch-roller rotational property of the pinch roller based on one or more pinch-roller rotational parameters sensed while the strap is being fed around the strap chute;

determine whether a slip condition has been met based on a comparison of the drive-roller rotational property with the pinch-roller rotational property; and

responsive to determining that the slip condition has been met, change at least one of the one or more actuator control instructions to reduce the rotational speed of the drive roller in a next strap-feeding cycle.

2 . The strapping machine of claim 1 , wherein the controller is further configured to stop the strap-feeding cycle by controlling the actuator to stop the drive roller from feeding the strap around the strap chute.

3 . The strapping machine of claim 1 , wherein the drive-roller rotational property comprises an average rotational speed of the drive roller, wherein the pinch-roller rotational property comprises an average rotational speed of the pinch roller, wherein the controller is further configured to determine the average rotational speed of the drive roller based on multiple drive-roller parameters sensed during a designated time period, wherein the controller is further configured to determine the average rotational speed of the pinch roller based on multiple pinch-roller rotational parameters sensed during the designated time period.

4 . The strapping machine of claim 1 , wherein the drive-roller parameter comprises one of a rotational speed, an angular increment, and a quantity of rotations, and wherein the pinch-roller parameter comprises one of a rotational speed, an angular increment, and a quantity of rotations.

5 . The strapping machine of claim 1 , wherein the controller is further configured to, responsive to determining that the slip condition has not been met, change at least one of the one or more actuator control instructions to increase the rotational speed of the drive roller.

6 . A method of operating a strapping machine, the method comprising:

during a strap-feeding cycle, driving an actuator in accordance with one or more actuator control instructions to drive a drive roller to feed a strap around a strap chute of the strapping machine;

determining a drive-roller rotational property of the drive roller based on one or more drive-roller rotational parameters sensed while the strap is being fed around the strap chute;

determining a pinch-roller rotational property of a pinch roller based on one or more pinch-roller rotational parameters sensed while the strap is being fed around the strap chute, wherein the pinch roller forms a nip with the drive roller sized to receive the strap therethrough;

determining whether a slip condition has been met based on a comparison of the drive-roller rotational property with the pinch-roller rotational property; and

responsive to determining that the slip condition has been met, changing at least one of the one or more actuator control instructions to reduce the rotational speed of the drive roller in a next strap-feeding cycle.

7 . The method of claim 6 , further comprising stopping the strap-feeding cycle by controlling the actuator to stop the drive roller from feeding the strap through the strapping machine.

8 . The method of claim 6 , wherein the drive-roller rotational property comprises an average rotational speed of the drive roller, wherein the pinch-roller rotational property comprises an average rotational speed of the pinch roller, the method further comprising:

determining the average rotational speed of the drive roller based on multiple drive-roller parameters sensed during a designated time period; and

determining the average rotational speed of the pinch roller based on multiple pinch-roller rotational parameters sensed during the designated time period.

9 . The method of claim 6 , wherein the drive-roller parameter comprises one of a rotational speed, an angular increment, and a quantity of rotations, and wherein the pinch-roller parameter comprises one of a rotational speed, an angular increment, and a quantity of rotations.

10 . The method of claim 6 , further comprising, responsive to determining that the slip condition has not been met, changing at least one of the one or more actuator control instructions to increase the rotational speed of the drive roller.