VI COMBINING SOLUTION PRINCIPLES (CONCEPT VARIANTS)
Product Application: Bilge Water Removal Product
We seek to "design a device to remove water from the bilges of unattended pleasure boats." The customers require natural energy sources. Example energy sources include wind, boat movement relative to mooring post, boat movement relative to water, electricity (battery-not a natural source!!), fuels (not a natural source!!), solar, water temperature differences, differences in concentrations (salt water), reactive compounds (e.g., Alka-Seltzer), falling rain, wave movements, pressure variations (hydrostatic), and water movement relative to a mooring post.
Based on the overall need of removing water automatically, performance metrics include removal capacity (minimum of 8 L/hr), durability in salt water and exposed to weather, minimize tool usage, stowable in a small volume, cost < $50, life; ≥10 years, size < 1 cubic meter.
Figure 10.20 shows the black box model for the product (after Hubka, Andreasen, and Eder 1988), and Figure 10.21 illustrates the functional model for the operation phase of the water removal device. Based on the functional model, directed search is used to generate solution principles to the product functions, as documented in the morphological matrix of Table 10.15. Combinations are then developed, focusing on alternative energy sources. Table 10.16 and Figures 10.22 through 10.26 show the results. Notice in the concept figures that mapping ideas from the morphological matrix to actual geometry is nonlinear and filled with design decisions. Again, sketches are needed, which must be continually refined and modified through iteration
Product Application: Smart Spoon to Assist Persons with Disabilities
The goal of this product is to design a device to facilitate the handling of kitchen utensils in a single orientation by persons with disabilities. The primary market consists of current and future students in secondary school. The secondary market consists of other persons with similar disabilities who are unable to use a kitchen utensil.
The customer needs listed for the smart spoon are shown in Table 10.17. The needs "operable regardless of skill level" and "provides correct orientation" require explanation. The first means that the users are assumed to lack certain cognitive skills and are not able to distinguish between the correct and incorrect ways to hold a spoon. If they are given a normal spoon and hold it wrong, they cannot scoop up food from the plate and are frustrated as a result. The second need indicates that a device is required that will cause the spoon to be oriented in such a way that its bottom surface is parallel to the ground or table ( 0° to the horizontal ), and once this orientation is achieved, any further twist of the wrist must produce a corresponding change in the orientation of the spoon. Thus, when the spoon is turned around by 180° from the horizontal, it drops the food (hopefully into the mouth).
Product specifications provide a quantitative measurement of a subjective need and are used to evaluate the performance of a product against a particular need. They contain a metric and a value that represents the target to be achieved. Product specifications for the more important needs are tabulated in Table 10.18.
The black box model in Figure 10.27 graphically defines the main function of the product. In this device, the function is to orient an eating utensil. Decomposing this main function, the function structure for the product is shown in Figure 10.28.
Using the functional decomposition, a morphological matrix is constructed. Each of the product functions is considered individually, and ideas are brainstormed to achieve the necessary function. Figure 10.29 shows a partial morphological matrix for the spoon. Some of the more promising ideas from the morphological matrix for each of the product functions are listed as follows. The cylindrical shape to "accept" the user has perfect symmetry and will be easy to manufacture. People lacking certain cognitive skills would have no problem identifying a correct side or position. It also has benefits of providing rotation as a means of orienting.
The term hard lock implies a situation where there can be no relative rotation between two surfaces, whereas the soft lock provides a partial locking, in that limited relative rotation still exists. The former is useful in providing a single orientation, whereas the latter helps to provide a continuous orientation (angle of spoon to horizontal is always close to zero). In addition, the pin lock, shown in the figure, provides positive locking, unlike friction locking or locking utilizing a magnetic field. Based on these function solutions, a number of concept configurations are generated. The configurations below provide examples.
Configuration 1: Built-up Handle
The built-up handle configuration is the simplest considered. Basically, this configuration is designed to increase the size of the handle on the spoon and provide a better surface for gripping the handle (Figure 10.30). There are three different parts involved in this, as shown in Figure 10.31.
Configuration 2: Pre-position Configuration
The pre-position configuration, as shown in Figure 10.32, is the first module designed to orient the spoon into the correct position before it is picked up. This concept relies on an eccentric weight attached to the cylinder to rotate the spoon into the correct position when it is set on the table (Figure 10.33).
Configuration 3:Pre-position with Hand Locking Configuration
The pre-position with hand locking configuration, shown in Figure 10.34, is an architecture that incorporates rotating the spoon into the correct position and locking it into position when it is picked up. These functions are accomplished by allowing the spoon and inner cylinder to rotate with respect to the table by lifting it off the surface with two brackets (Figure 10.35). These brackets allow the entire inner cylinder to rotate and orient without having to move on the table surface. This behavior is very important when the user sets their food on a towel or other surface where the pre-position module could not rotate into correct position.
The guard in this configuration has been moved to the rear of the inner cylinder to keep it away from the user's face. While this location is not necessary for the operation of the spoon, it makes the device less obtrusive and helps keep the spoon balanced in the user's hand.
Configuration 4: Pre-position with Weight Locking
Another architecture for the assistive utensil is the preposition with weight (friction) locking configuration (Figure 10.36). This architecture is the most complex and advanced configuration, because it uses a mechanical lock to orient the spoon and then hold it into position. The spoon looks similar to the pre-position configuration, except that an outer cylinder is added over the inner cylinder and the locking mechanism is attached to the end of the spoon. The exploded view in Figure 10.37 shows the different parts used in the construction of this spoon.
VII. SUMMARY AND «GOLDEN NUGGETS"
Concept generation represents the time when product function and architecture are transformed to actual geometry. This stage in product development is exciting and challenging. It is the time when creativity and design principles are used to create innovative solutions. It is also the time when the first glimpses of a realized product appears from the design teams' inner thoughts and dreams.
During the concept generation process, solution principles and concept variants should be based on the following:
Preference should be given to main product functions that determine the working principle of the overall solution system.
Drawing and visual thinking should be tapped and encouraged to realize innovative solutions.
Classifying criteria should be derived from identifiable relationships between energy, material, and signal flows; that is, functional models should be used to suggest classifying criteria.
If the physical working principle is unknown, it should be derived from physical effects. If it is known, the form design features (surfaces, motions, and materials) should be chosen and varied.
Combinations of intuitive concept generation and directed-search methods should be used to explore a breadth of concept ideas.
Final product concepts are not the first ones generated. Many concepts must therefore be explored, seeking continual additions and refinements.