Optimal control of elevators

The paper deals with optimization approaches in vertical transport, and with criteria for optimal control of single-unit and multi-unit elevator systems. The advantages and drawbacks for different performance indices are reviewed, and a performance index unifying all advantages is indicated. Three optimal-control modes, differing in mode of feed of the waiting and admission information, are suggested. The optimal travel and admission policy is obtained with the aid of multivariate functional equations. Also presented are an algorithm for the functional equations and an identification method for the variables affecting the optimal policy. The relevant relationships are reviewed, and an on-line control method is proposed. Results and examples are given in Appendix I, and standard collective systems are compared in Appendix 2.