Abstract: An automated order fulfillment system and mobile robot are disclosed, where the mobile robot includes a compliant drive for moving between levels of a multilevel storage structure. In one example, the compliant drive comprises a drive shaft having splines configured to provide rotational play that prevents jamming of a vertical drive gear on the end of the shaft with a rack in a vertical track.

Abstract: An oil-in-water monitor for monitoring the effluent of an oil-water separator. A pressure vessel coalesces oil from the effluent and gathers the oil in a collection section which is automatically emptied after an hour. If more than a predetermined amount of oil is gathered in the hour, an oil-sensing probe sends a signal to activate a warning light valve which permit pipes to return the effluent to the separator.If the effluent becomes too turbid, a turbidity senser activates an alarm and the valves which permit pipes to return the effluent to the separator.If the coalescer unit clogs, an indication is given by a differential pressure gauge.