ME218d Smart Product Design
|ME218d is the fourth and final quarter in the Smart Product design sequence. In this course, students who have completed the preceding three courses (ME218abc) work with industrial partners on projects of direct industrial relevance. In conjunction with the industrial partners, teams of 3-4 students apply the information and design processes learned in ME218abc to translate a one page project description into a set of performance specifications. The teams then proceed to design, document and construct a working prototype device to meet those specifications. In parallel with the project work, a lecture series covers more advanced material such as comparative micro-controller architectures, chip level microcontroller system design, features and selection of real time kernels and alternatives among existing high-level-language programmable controllers.|
|The course was first offered in the fall of 1994. Since that time, student teams have taken on projects from partners as large as Raychem and as small as Virtual Technologies (< 10 employees). The projects have allowed the partners an opportunity to work with a talented group of masters students who bring new ideas and insights to the projects.|
|In general, the projects taken on by the student teams are ideas that are of immediate interest, though not critical importance, to the partners. In some instances, the partners are looking for the kind of fresh ideas that come from a group without the local corporate mind-set. In other cases they are projects for which no in-house resources exist, either technically or from a manpower standpoint. The projects all share the common characteristic of requiring the tight integration of mechanical systems with electronics, microprocessors and software.|
|Industrial partners begin the projects by contacting Dr. Carryer during the summer recess. Working in collaboration with Dr. Carryer they develop a one page description of the problem. At the beginning of the fall quarter the students will specify project preferences based on these problem descriptions and their personal interests. Using this information, teams are formed and the project work begins. At this time partners may request that the team members enter into non-disclosure agreements if the project will require the students to have access to trade secret information. The students work on the project throughout the fall quarter and deliver a final report, public presentation and working prototype at the end of the fall quarter.|
|The financial commitment for the partner is twofold. Each project incurs a laboratory fee of $9000. In addition, the partner company is responsible for the direct costs associated with the construction of the prototype device. Depending on the sponsor's wishes, the purchasing for these direct costs can be done through the company or through Stanford and billed to the company.|
Sampling of Past Projects
|The process development group at Raychem was seeking a way to improve the control of an existing extrusion machine. The extrusion machine is used to produce one of Raychem's mainstay products: Heat Shrink Tubing. In the extrusion process it is very important to maintain a uniform wall thickness in the finished tubing. The existing extrusion process employs a human operator who periodically checks the readings on a wall thickness gauge and if necessary adjusts the extruder die. This approach resulted in long startup times while the initial die setting was adjusted. It also resulted in the scrapping of an in-process spool of tubing if the wall thickness ever went outside the maximum tolerance. The student team designed and constructed a modified extruder head that could be controlled by a microprocessor. This microprocessor communicated with the wall thickness gauge to form a closed loop system that constantly monitored and adjusted the wall thickness to remain within tolerance. In the process of developing this solution, the student team also discovered the source of a long standing issue related to a rotational offset between the wall thickness gauge and the required adjustments to the extruder head.
Students: Ayad Al-Sheik, Aaron Barzilai and Phil Chen.
For AFX Inc., the goal was to produce a dramatic demonstration platform for the mapping capability provided by the sponsor. For this project the students acquired and built a commercial 6' dia. helium filled blimp kit. The goal was to make this blimp capable of determining its location by triangulating on IR beacons and autonomously following a specified course and then maneuvering into a dock. To this end, the students fitted the blimp with a local microprocessor, IR beacon tracking system and radio modems for communications with a workstation running the partner's mapping and navigation software. Very early in the project, it became clear that the principle driving force in the design was to minimize weight in order to fit within the payload capabilities of the blimp. In an effort to increase the useful payload to accommodate the added navigation and communications systems, the team ultimately discarded, re-designed and re-built the payload gondola and all of the flight control electronics save for the final power stage. When the student team discovered a high degree of coupling in the attitude control system of the blimp, they implemented digital control algorithms in the local micro-processor that effectively de-coupled the attitude commands and significantly eased the task of guiding the blimp.
Virtual Technologies is a small Palo Alto company that manufactures an instrumented glove that is used as a computer input device by virtual reality researchers. In order to track the position of the hand within a virtual world, the company currently employs a commercial sensor system based on electro-magnetic field strength. The existing system has a relatively slow update rate and is very sensitive to the presence of ferrous metals in the sensing field. The student team was asked to come up with an apparatus to track the position of the hand while overcoming the limitations imposed by the current sensor system. In response to this challenge, the team designed and fabricated a light-weight articulated mechanism using carbon fiber tubing. The most unique aspect of the design is a novel rotational sensor that was used to track the articulation angles of the mechanism. Virtual Technologies is in the process of applying for a patent on the sensor system developed for this project.