In our Embedded Double Engine System (E-DES) models two type of redundancy (Back-up) methods used. These are methods usually used in systems which need high reliability.
1) Passive redundancy method used to carry out normal functions of parking even if, one of the main motor develop an electrical snag. The main drives which controls the up-down, left-right and lateral movement comes with twin motors. That means in worst case, if one of the motors fails, the Circuit breaker automatically disconnects that motor from power but the paired motor continues the operation. Only thing the speed of the operation can be reduced till the trouble being rectified.
2) Active redundancy is a design concept that increases operational availability and that reduces operating cost by automating most critical maintenance actions. He-Man Robopark Tower uses this method in designing its special purpose sensors. Triple modular redundancy (TMR) system is used in the sensor logic. In a triply redundant sensor system, the system has three sub sensor components. Since each one rarely fails and the sub components are expected to fail independently the chance for the failure of more than one at the same time supposed to be near zero. An error in one sensing component may then be out-voted by the other two. So the system still works normally by the voting logic and same time a maintenance alert is triggered. The failed components can be rectified later when the tower is empty OR after hours.