Problem Approach

PROBLEM APPROACH:

The team was assigned with designing a semi-autonomous device for assisting an elderly individual complete a daily task. In order to determine what daily tasks posed difficulty, a customer survey was generated. Using the customer survey, information was gathered which showed possible areas to explore for the design project. With the gathered information, the group devised numerous design concepts, ranging from tabletop devices used to open medication containers to human-assisted mobility devices. To refine the concept selection, a brainstorming session was conducted where the concepts were rated according to feasibility, uniqueness, safety, and marketability. The nominal group technique, which allows individual group member to submit votes for their preferred designs, and a market analysis was utilized to rate the final round of concepts. Utilizing these techniques, the group chose to pursue a Medication Container Opener.

The next step was to generate a list of customer needs more specific to the Medication Container Opener. Engineering characteristics were created to address the different customer needs. The next step was to prioritize the customer needs. Finally a House of Quality Matrix was created to help prioritize the engineering characteristics and establish target values.

The next stage was the concept generation stage. This stage involved designing solutions to sub problems before integrating into the larger complete machine. The first step was to develop a reference design to be used as a benchmark for subsequent concepts. In this machine, each individual motion in the opening process had its own motor/actuator to drive it. Once this design was complete, following concepts were optimized to reduce the number of motors and introduce synchronized motions.

The size of the machine will be primarily driven by the size and type of the containers that will be opened. Furthermore, other factors that will influence the physical attributes of the machine include the devices utilized to carry out the motion operations. Another important factor that will influence the final design of the machine will come from customer needs. Using this information, the group will pursue a design that will satisfy the objective set forth.

ANTICIPATED PROBLEMS:

The most difficult aspect of this design is in constructing a machine that can recreate the compound functions of a human hand. The human hand is a highly sensitive closed loop device that can simultaneously perform complex motions. A person is able to grip the container by closing their hand around it which applies a normal force to the surface and exerts a lateral force to engage a safety mechanism on the closure. The last step is to twist the closure while allowing it to rise on the threads, but still exert some downward force to keep the safety mechanism engaged. In order to accomplish this, the container or the closure must turn; doing so will cause the container and closure to separate. However, there are certain types of containers that do not need to be rotated in order to open; these simply lift off. In those cases, there is no adverse affect of rotating the container; therefore, the same sequence of motions can be applied. Another approach to the lift-off type closures is to incorporate a mechanism similar to that of a bottle cap opener. A mechanical device needs to have series of motions and sub devices to complete the same task, each of which require a separate drive and control. Creating a device that exactly mimics these motions would have a complexity and cost beyond the scope of the project.

The many types of containers that exist pose a problem for the design group. Due to the abundant types of opening mechanisms, the challenge of creating a simple machine that emulate all types of opening mechanisms is beyond the scope of the project. In order to design and create a prototype within the given time period, the group must focus on proving the concept that the human hand can be emulated in performing the operation of removing the closure from the container. Therefore, the types of containers to open must be limited. As a result, the approach to this problem was determined to be limiting the types of closures that would be opened.

Other concerns with this project are inherent safety issues involved with rotating components. There is a potential hazard for the operator to place there hand on a piece of rotating part. This action can potentially result in a severe injury or loss of appendages. There are also lateral forces applied to the container and closure during operation. Even though these forces may be minimal, there is the possibility that the operator can be injured. This device is intended for elderly individuals who have a limited knowledge of current technology; their diminished mental capacity means that the device needs to be able to operate with minimal user input. The device must be able to perform safety checks to ensure that the container will not be compromised and the user will not be injured.