A substrate bonding apparatus for fabricating an LCD device aligns upper and lower stages to accurately bond first and second substrates. More specifically, one or more than one phase generators are used for the robot system and one of the plurality of controllers is selected depending on the generated phase. The number of inductors of a filter section that arc wound around different magnet cores can be reduced by equivalence transformation. The tire mounting positions is identified by comparing values of the control voltages thus controlled. Moreover, when resources are released by a request, the resource allocation system may place the resources in a temporary holding area until the resource allocation returns to the top of the ordered plan so that lower priority requests that are lower in the plan do not take resources that are needed by waiting higher priority requests higher in the plan.