EE192: Mechatronics Design Lab Spring 2013

submission instructions

Due on (some date). Please (submission instructions).

proposal outline

The purpose of the project proposal is to give you early feedback on your design ideas, to help to steer you away from some of the common design ﬂaws. A good motto to keep in mind is ‘‘measure twice, drill once’’. The pace of the rest of the course is quite fast, and now is the time to plan what equipment you want, and where it should be mounted. It can be very difficult to try to squeeze in one more chip, or one more switch after your whole system has been constructed. The project proposal is a non-trivial amount of work; we would like to see 10 hours of effort per team member. Please read the NATCAR rules from the UC Davis site. Here is an outline for you to follow:

Overall strategies (1 page) (20%): Think about “winning” strategies. A “winning” strategy is one which results in a functional, thoroughly tested, and reliable vehicle with a minimum of effort. Separately list essential and “wouldn’t it be great to have…” features. A good rule of thumb is that you would like to be 80% complete with 20% of budget. Then you have budget to solve the remaining hard problems. Now speed is of course an important consideration, but speed without stability and robustness won’t get you far. Will your vehicle rely on raw speed, expert navigation, expert braking, etc? How does your strategy affect the types of sensors and control strategies you will use? List anticipated sensor needs and how they will be used. (Estimate number of lines of digital and analog I/O you will use.)

Hardware design: Attachments (1 page) (5%): List every attachment you anticipate adding to your vehicle. (You are not committing to adding these devices, just leaving room for them if desired). Some possible things to attach: CPU board, IO board, battery pack, DC-DC converter, user interface, sensors, etc.

Hardware design: Detailed mechanical drawings (2 pages) (20%): Draw a detailed layout of the vehicle with attachments from section 2.1. Include dimensions of circuit boards and vehicle. Expected detail is to level of screw holes for what you need to mount. Show location of ﬂag mounting post, emergency stop switch, and battery pack. Do some rough sketches ﬁrst: can you change the battery pack without unscrewing anything? Are switches for mode/power/reset readily accessible? Have you left room for expansion circuitry components if needed? (SolidWorks CAD software is available in Cory 204). Include a labelled photo which indicates good locations for mounting an encoder wheel for speed sensing.

Hardware design: List of special materials (0.5 pages) (5%): Do you need metal or plastic brackets? Metal or plastic plates? Special switches or connectors? If there is enough interest, we can arrange car pools to TAP plastics or Fry’s. We also will put together periodic class mail orders to Digikey.

Hardware design: Motor drive circuitry (1 page) (30%): Show a detailed schematic for your motor drive circuitry, including values and pin numbers. Draw expected parts layout. Is there room for heatsinks? (See hand out for example of a detailed schematic/parts layout.)

Software strategy (confidential!) (1 page) (20%): Describe in some detail what you expect a good software strategy to be. How much effort will be extended on for example, precise steering, precise speed distance/velocity, error recovery? List those things you need to understand more completely before you will be able to design your software. State your assumptions about what quality of sensors you are assuming. Make a ﬁrst pass, high-level block diagram of the software system. (A block diagram should be like in CS150, showing functional modules and their interconnection, not a ﬂow chart.)