Abstract: A load sensor compares generated values of load signals to predicted values of the load signals. Where an error between a generated value and a predicted value is less than a threshold, a value of zero is transmitted by the load sensor to an external systems, in an encoded stream of bits, and the error are used to calculate a predicated value of a next load signal, such that insubstantial changes in loading resulting in small errors are not transmitted to the external system. Where an error between the generated value and the predicted value exceeds the threshold, however, a value representative of the error is transmitted to the external system, in an encoded stream of bits. The external system processes the stream of bits to calculate the error, to determine that an item has been placed on a storage system or removed therefrom, or to identify the item.

Abstract: An apparatus includes a platform or other accessory that is supported by one or more transducer assemblies using piezoelectric transducers. In one implementation, a saddle structure provides mechanical support to a platform while transferring force from a load onto a portion to which a pair of piezoelectric transducers are affixed. As a load on the saddle changes, the resulting change in strain on the portion produces signals from the piezoelectric transducers. In another implementation a beam provides mechanical support to a platform or other accessory. A pair of piezoelectric transducers are affixed near a strain concentrator, such as a hole in the beam, produce signals indicative of a change in load on the beam.

Abstract: An impulse strip including a plurality of clips, hooks or other features for attaching items to the impulse strip also includes a plurality of switches associated with each of the clips, hooks or other features. The switches are in communication with illuminators or other indicators that are arranged in an array. When an item is loaded onto the strip, or removed from the strip, a switch may be opened or closed, causing one of the illuminators in the array to be activated or deactivated accordingly. An image captured of the illuminators is processed to determine which of the illuminators is activated and which is deactivated, and an inventory level of the strip may be determined based on the statuses of the respective illuminators corresponding to the clips, the hooks or the other features of the impulse strip.