Converting the User Requirements into an Elevator Traffic Design: The HARint Space

A previous paper introduced the concept of the HARint plane, which is a tool to visualise the optimality of an elevator design. This paper extends the concept of the HARint plane to the HARint space where the complete set of user requirements is used to implement a compliant elevator traffic design. In the HARint space, the full set of user requirements are considered: the passenger arrival rate (AR%), the target interval (inttar), the average travelling time (ATT) and the average waiting time (AWT). The HARint space provides an automated methodology in the form a set of clear steps that will allow the designer to convert these four user requirements into an elevator traffic design. As with the HARint plane method, the target interval is used in combination with the expected arrival rate (AR%) and the building population, U, in order to find an initial assessment, the number of passengers expected to board the elevator. The target average travelling times then used to select a suitable elevator speed. This is then used to calculate the round trip time and then select the optimum number of elevators. An iteration is then carried out to find the actual number of passengers, and hence the elevator capacity. A check is then carried out to ensure that the average waiting time has been met, and if it has not been achieved, then a further iteration is carried out. While the HARint plane provides the optimum number of elevator cars to achieve the two user requirements, the HARint space provides the optimum number of elevator as well as the optimum rated speed to meet the four user requirements of arrival rate, target interval, average waiting time and average travelling time. An obvious consequence of the introduction of the average travelling time as a user requirement is that the speed becomes an outcome of the HARint space. The method also triggers a zoning recommendation in cases where the average travelling time cannot be met by varying the speed within reasonable limits.