A system and method for detecting delivery items includes a hardware processor that is operably connected to a light detector and a camera positioned at a sensing location along a moving surface that moves a delivery item. The processor may be configured to perform operations that include receiving a light status signal from the light detector, the light status signal having a first state when a light beam directed across the moving surface is detected at the light detector, which indicates absence of the delivery item, and a second state when the light beam is not detected at the light detector, which indicates presence of the delivery item, receiving image data from the camera, which includes images at the sensing location, and modifying the light status signal based on the image data when the light status signal and the image data disagree on the number of delivery items.

A sorter system is configured to sort objects disposed on a conveying surface to multiple locations. The system includes a frame, a plurality of carriages each having a motor, a belt, and a plurality of pulleys. The sorter system includes a power line extending through the frame and power pickups on one or more carriages to receive power from the power line and provide power to actuate the belts of two or more carriages. The sorter system also includes a control line extending through the frame and one or more master carriages configured to receive control signals from a sorter controller system to control actuation of the belts of two or more carriages. The carriages may include a belt drive system configured to reduce the widths of the carriages. The belt drive systems may drive the belts on-center to reduce the torque and energy required to actuate the belt.

A sorter system is configured to sort objects disposed on a conveying surface to multiple locations. The system includes a frame, a plurality of carriages each having a motor, a belt, and a plurality of pulleys. The sorter system includes a power line extending through the frame and power pickups on one or more carriages to receive power from the power line and provide power to actuate the belts of two or more carriages. The sorter system also includes a control line extending through the frame and one or more master carriages configured to receive control signals from a sorter controller system to control actuation of the belts of two or more carriages. The carriages may include a belt drive system configured to reduce the widths of the carriages. The belt drive systems may drive the belts on-center to reduce the torque and energy required to actuate the belt.