Abstract: Each transport device contains at least two drive wheels which are driven at individual speeds V.sub.A and V.sub.B and which are pivotable by related steering angles .alpha. and .beta.. Identical servo-drive units are associated with the drive wheels and their mode of operation and mutual coupling is adapted by switch devices to the steering angles .alpha. and .beta. such that the required speed adjustment must not be computed in accordance with the relationship V.sub.B =(cos.alpha./cos.beta.). V.sub.A but the speed is automatically adjusted through the entire steering angle range of -90.degree. to +90.degree.. At .alpha.=.beta.=0.degree. the leading servo-drive unit is rigidly guided by its speed regulation loop as a MASTER servo-drive unit and its armature current is supplied as a reference magnitude to the armature current regulation loop of the trailing servo-drive unit which is operated as a SLAVE servo-drive unit. At .alpha.=.beta.=.+-.90.degree.

Abstract: The passive track system comprises a passive track formed as a highly reflective strip adhered to the floor and containing a bar code, vehicle-supported passive track reading devices for forward and reverse travel as well as a bar code reading device. The passive track system can be operated as a passive track guidance system or as a passive track control system or both. The vehicle follows the passive track or guide path by continuously monitoring the travel lane on both sides of the central longitudinal axis of the vehicle using track sensors located in reading heads. In the method, sets of actual values thus measured are cross-correlated with a set of reference values corresponding to the track positions and stored in an electronic evaluation device. The appropriate cross-correlation function is calculated for each "observation" using a special track guidance algorithm and then a track position of the vehicle as well as a quality or system condition factor for the passive track system are derived.

Abstract: Transponders are arranged at control locations associated with sections of a track or travel path. Each transponder is in wireless communication through an inductive transmission path and an optical transmission path with a conveyor present in the operable range of the transponder. Each transponder is in communication with a central system control via an associated group control unit by means of two-wire lines or conductors. The operational mode of each transponder is controllable by means of a multiplexer such that the transponder operates either as a responder or answering device with simultaneous unidirectional signal transfer and which responder is to be interrogated by a conveyor or as a bidirectional signal transmitter. The apparatus selectively functions as a location or site code transmitter and presence indicator for the individual conveyors or as bidirectional data transmitter with isolated directions between the conveyors and the central system control.