Identifying the Measures of Merit for the LEMFEV Using the House of Quality Chart

In our project, we used the house of quality chart, exemplified in Fig. 1, to identify the measures of merit for subsequent optimization. Fig. 2 provides the legend for the chart.

Figure 1 - LEMFEV, the House of Quality Chart

Figure 2 - LEMFEV, the House of Quality Chart legend

Indeed, the purpose of this diagram is to help the designer understand which requirements are of greater importance than others and how this complicates the development of the product, in our case - aircraft.

Typically, this diagram includes customer requirements (listed down the left side of the chart), aircraft parameters (listed across the top), correlations between parameters ("roof"), interrelationships between requirements and parameters (the central matrix). Also, there is space across the bottom of the chart to write in the target values for parameters.

Based on the chart data, we conducted trade studies to compare the versions of our UAV (Fig. 3).

Figure 3 - LEMFEV, comparison of the UAV's versions using the house of quality chart data

The customer requirements, including reliability, payload mass, range, speed, and endurance, as well as the power available for instruments and the allowable mass of the data transmission system, were converted into aircraft parameters and properties. The analysis showed that in order to bring the maximum value to Mars exploration, the Martian airplane needs a power system that would feature the maximum possible operational time at the given payload mass. This will permit the expansion of the range of measured parameters on a spatial and temporal scale. The operational time may be extended either by ensuring the overnight flight of a solar single-flight airplane or by providing a solar rechargeable airplane with a vertical take-off capability.

Among the customer requirements, the most important is the reliability and technical maturity of the UAV, which can be expressed, e.g., in terms of the mean operational hours before failure. At this early conceptual design stage, this requirement may be addressed by selecting systems and components with known and appropriate reliability characteristics.