Ongo01c Project OSCAR Power

Ongo01c Project OSCAR Power Fall 2003 Project Plan Version 2.0 Client: Department of Electrical and Computer Engineering, Iowa State University Faculty Advisor: Dr. Ralph E. Patterson III Team Members: Marquis, Daniel Nguyen, Hong 10 October 2003

Revision History Date Author Description Version 22 September D. J. Marquis Document Inception 1.0 2003 26 September D. J. Marquis Document Revision 1.5 2003 26 September D. J. Marquis Document Revision 1.6 2003 2 October D. J. Marquis Document Revision 1.7 2003 9 October Hong Nguyen Document Revision / Corrections 1.8 2003 10 October D. J. Marquis Document Revision / Corrections 1.9 2002 10 October 2002 Hong Hguyen Document Revision / Corrections 2.0

Table of Contents 1. Introduction...1 1.1 Abstract...1 1.2 Acknowledgement...1 1.3 Problem Statement...1 1.3.1 Primary Problem...1 1.3.2 Secondary Problem...2 1.3.3 Tertiary Problem...2 1.4 Operating Environment...2 1.5 Intended Users and Uses...2 1.6 Assumptions and Limitations...2 1.6.1 Assumptions...2 1.6.2 Limitations...3 1.7 Expected End Product...3 2. Proposed Approach and Statement of Work...4 2.1 Functional Requirements...4 2.2 Design Constraints...4 2.3 Technology Considerations...4 2.4 Technical Approach Considerations...4 2.5 Testing Requirements Considerations...4 2.6 Security Considerations...4 2.7 Safety Considerations...4 2.8 Intellectual Property Considerations...5 2.9 Commercialization Considerations...5 2.10 Possible Risks and Risk Management...5 2.11 Proposed Project Milestones and Evaluation Criteria...6 2.11.1 Find DC-DC Converters...6 2.11.2 Create Power Budget...6 2.11.3 Verify Battery Status...6 2.11.4 Verify Battery Indicators...6 2.11.5 Test DC-DC Converters...6 2.11.6 Fuse protection...6 2.11.7 Research for Temp Sensor Power Solution...6 2.11.8 Built & Installed Temp Sensor Power Solution...6 2.11.9 Test Temp Sensor Power Solution...6 2.13 Statement of Work...7 2.13.1 Problem Definition...7 2.13.2 Technology and Implementation Considerations and Selection...7 2.13.3 End-product Design...7 2.13.4 End-product Prototype Implementation...8 2.13.5 End-Product Testing...8 2.13.6 End-Product Documentation...8 2.13.7 End-Product Demonstration...8 2.13.8 Project Reporting...8 3. Estimated Resource Requirements and Schedules...10 3.1 Estimated Resource Requirement...10 3.1.1 Financial...10 3.1.2 Personnel Effort...10 i

3.2 Schedules...11 4. Project Team Information...14 4.1 Client information...14 4.2 Faculty advisor information...14 4.3 Team member information...14 5. Closing Summary...15 ii

Table of Figures Figure 3-1 Power sub-team schedule of tasks...12 Figure 3-2 Power sub-team schedule of deliverables...13 iii

Table of Tables Table 2-1 Power sub-team measurable milestones...6 Table 3-1 Power sub-team financial budget...10 Table 3-2 Power sub-team personnel effort budget...10 Table 3-3 Power sub-team major tasks schedule...11 Table 3-4 Power sub-team deliverables schedule...11 iv

List of Definitions: DC-AC inverter = An electronic device that changes DC current to alternating current, usually to simulate a regular household wall socket power supply. DC-DC inverter = An electronic device that changes a DC power supply's voltage level to a different voltage level, usually to meet power supply specifications of a load. OSCAR = Octagonal Speech Controlled Autonomous Robot v

1. Introduction Project OSCAR (Octagonal Speech Controlled Autonomous Robot) is an ongoing senior design project funded by the Department of Electrical and Computer Engineering (ECpE) at Iowa State University (ISU). Its purpose is to maintain and improve robotic ambassadors for the department. Past robots include Zorba and CYBOT. The most recent robot is OSCAR. None of the robots are completely operational at the moment. Zorba no longer exists. CYBOT is aging and no longer works. OSCAR is in need of some new hardware, some new software, and a new power supply. The power sub-team is a part of Project OSCAR. The power sub-team has been tasked with solving OSCAR s power supply problems, which have helped prevent it from giving effective demonstrations and fulfilling its role as a departmental ambassador to the community. Recent power supply problems resulted from a change in computer hardware. In Spring 2003, a new computer was installed that consumed 300% the power of the old computer. This caused a DC-DC converter that was built that semester to be overloaded and never fully implemented. This semester, however, a more energy efficient computer (PC 104) will be installed and the DC-DC converter should, once again be sufficient. 1.1 Abstract The robot OSCAR, whose purpose is to serve as an ambassador to the public for ISU's department of ECpE, is unable to give significant demonstrations. This inability is partially due to an inefficient power supply. To solve this problem, an efficient DC-DC converter was designed and built over a year ago. It was to power the main system components and replace OSCAR's inefficient DC-AC-DC power supply system. Unfortunately, the DC-DC converter was never fully installed and tested. The Fall 2003 power team's goal is to finish installation and testing of the DC-DC converter and to provide at least a temporary on-board power solution to any subsystem not served by the DC-DC converter. With a complete and more efficient power system installed, OSCAR will be one step closer to performing meaningful demonstrations for the public; and therefore will be one step closer to fulfilling its role as an electronic ambassador. 1.2 Acknowledgement The help of the OSCAR project advisor, Prof. Patterson, and the cooperation of other OSCAR sub-teams will prove indispensable to the success of the OSCAR power subteam s part of the project. 1.3 Problem Statement Below are the two problems the power sub-team hopes to solve this semester. 1.3.1 Primary Problem Currently OSCAR is running a PC that uses a standard PC power supply. This supply is fed from a 12/120 DC/AC inverter. The inverter is powered by two twelve-volt, on-board batteries. The power sub-team views these two power supplies as a wasteful part of 1

1.3.2 1.3.3 OSCAR. The power that OSCAR has on-board is very limited. The goal is to minimize the losses in this subsystem (the PC) in order to save as much power as possible. This will be accomplished by first doing a power audit on OSCAR to verify that its current/future power needs can be met with the previously built DC-DC converter. If so, the DC-DC converter shall be tested and installed. If not, then an alternative shall be considered, and the project plan rewritten. Secondary Problem Currently, OSCAR's sensors are not connected to an on-board power supply; instead they are being powered by the wall outlet, which effectively requires OSCAR to be tethered at all times. Since OSCAR is an Autonomous Robot, this is unacceptable, and an on-board power supply must be implemented. This will be accomplished by a)finding and implementing a quick and easy way to supply sensors with on-board power, b) implementing such a quick fix, and c) starting to research a more permanent solution. Depending on workload, the sensors sub-team may take the lead in solving this problem. Tertiary Problem Maintenance and support for the existing power system must be provided so that other teams can test parts of OSCAR. 1.4 Operating Environment OSCAR is designed to operate in controlled, indoor environments. Exposure to excessive dust, EM radiation, heat, and physical abuse should be avoided. OSCAR is computer-based and its operating environment constraints are largely set by the operating environment constraints of its electronic components. An occasional drop or fall may occur, but should not be disabling. 1.5 Intended Users and Uses The power system is intended to serve all systems on board OSCAR. This includes the motion control team and their six DC motors, the sensor team and their sensor array, the software team and the on-board computer, and finally the end-effector team and the future arm they will provide. The power system is intended to supply power to OSCAR for demonstrations. These demonstrations last five minutes, fifteen minutes, half an hour, or even a few hours. The power system is not intended to provide power to non-related devices like home theater systems, full fledged desktop computers, electric lawn mowers, and halogen lamps. 1.6 Assumptions and Limitations Below are the assumptions and limitations the power sub-team used in creating its project plan. 1.6.1 Assumptions OSCAR s use will be limited to its general current demonstrative capacities. Sensitive power systems will be isolated. For example, the PC and sensors will not run off the same supply line as the motors. 2

Power requirements will not increase substantially without the power sub-teams first being notified and consulted so that adjustments can be made. 1.6.2 Limitations Power supplied can not exceed the batteries' ability to furnish power. The previously built DC-DC converters and sufficient documentation must be found. The ability of the DC-Dc converter to supply power is limited. The amount of time that each member can invest into the project is limited. There are only two members on the power sub-team this semester. This will require more time from each sub-team member in order to build the supplies, write reports, attend management meetings, and do presentations and demos. The power sub-team budget is currently $0; therefore, spending money should be avoided if at all possible. 1.7 Expected End Product The expected outcomes of this sub-team's project are: 1) a DC-DC power supply system for the computer 2) a power budget for OSCAR 3) a temporary on board power supply for sensors 3

2. Proposed Approach and Statement of Work Below are the requirements, constraints, considerations, milestones and end-product issues the power sub-team has selected. 2.1 Functional Requirements Power quality: Computer quality, +/-5V power must be supplied to the computer. Peak power availability: The amount of peak power available must exceed the maximum possible peak load (i.e. the load if all OSCAR systems were to perform their most power intensive processes at once). 2.2 Design Constraints Maximum power capability: Hours @ Ampere Load for 2 batteries working together are 11.6hr @ 5A; 3.2hr @ 15A; 1.7hr @ 25A. Minimum battery charge: battery should not be discharged below 50% (i.e. 12.24V) for any extended period of time (if possible). Damage may result. Operating conditions: OSCAR is intended to be used autonomously. Consequently, maximum battery life is required. Weight: all components must be as light as practical to allow for easier transportation of OSCAR and as to not over-work the motors and conserve energy. Size: both robots feature relatively small volume inside their cases. Components must be designed to fit within the case. 2.3 Technology Considerations The technologies to be used for the DC-DC converter have already been chosen and implemented. The technologies to be used for incorporating the sensors might include: rechargeable batteries, a DC-AC-DC converter system, and a DC-DC converter. 2.4 Technical Approach Considerations The technical approach used for choosing a temporary power supply for sensors (and any other system not hooked up to the DC-DC converter) will be quick. A solution will be searched for and evaluated based mainly on how quickly the solution can be implemented. In no case shall the solution cause demand for power to exceed available supply. 2.5 Testing Requirements Considerations The technical approach used for testing the DC-DC converter shall be systematic, incremental testing. The power supply shall be tested on its own for power quality, and voltage levels. Then every OSCAR subsystem shall be tested for shorts and be fused. Finally, OSCAR shall be tested with the battery installed one subsystem at a time and then all together. 2.6 Security Considerations Security is not a big concern for this project, though locking the senior design lab door is a very good idea. 2.7 Safety Considerations Batteries should not be pried open or exposed to excessive heat. Leakage of acid may result. 4

2.8 Intellectual Property Considerations Currently, the power sub-team is not aware of any intellectual property considerations. The only possible exception is the DC-DC converter design, which was pulled off the web. The design, however, seems to have been made for public use. 2.9 Commercialization Considerations There are no plans to commercialize OSCAR's custom built power supply. 2.10 Possible Risks and Risk Management Short circuit: (Risk level = Moderate) A short circuit may occur from components of other sub-teams. Protecting each sub-system individually will solve this problem. Resistance measurements will be made at the supply terminals for each sub system. This will provide the subteam with the information to set up protection for the short circuit current. Non availability of parts: (Risk level = Low to Moderate) If the power sub-team has to order parts and if the parts for the supply are not available, a delay will occur. Alternate sources may be available for parts, but it would take time to locate the alternate vendors. Multiple vendors will be considered to buy the parts from. Cost Risks : (Risk Level = Moderate to High) The power sub-team has a budget which does not allow replacement parts due to items being lost or stolen or broken. The risk level is Moderate to High, because the DC-DC converters are missing at the moment. To mitigate this risk the power sub-team shall make every effort to find any missing equipment and to lock up the Senior Design lab. Having an inadequate Power Source: (Risk Level = Moderate) If other teams increase their power usage without the power sub-team's knowledge, then the power supply may no longer be sufficient to power OSCAR, and demonstrations will not be possible. To mitigate this risk, the power subteam shall attend all team leader meetings. Over committed team members: (Risk Level = Moderate to High) The power sub-team members are seniors in electrical engineering at Iowa State University and have very little free time. There is no real way to mitigate this risk. Commitments have already been made for the semester. Uninformed team members: (Risk Level = High) The power sub-team members are both new to the project, there hasn't been a power sub-team in over a year, and documentation is barely sufficient. There is a high risk of the sub-team members being uninformed. Steps taken to mitigate this risk include: finding all the documentation available and talking to the project advisor. Future steps that will be taken include: contacting former team members and asking questions of second semester students. Loss of team member: (Risk Level = Low) Since the team is only composed of two people, loosing a member would be detrimental. The member s knowledge would be lost. The risk to the project from loss of a member shall be minimized through extensive communication between members. This will reduce the amount of knowledge that could be lost. Wrong Approach: (Risk Level = Medium) Much of the documentation is missing for the DC/DC converters, and that increases the risk of choosing the wrong approach. To minimize the risk of a taking a wrong approach, will find the documentation 5

2.11 Proposed Project Milestones and Evaluation Criteria Table 2-1 Power sub-team measurable milestones Ongo-01c Milestone Priority Completion DC-DC Converters Found High 20% Power Budget Created High 5% Battery Status Verified High 0% Battery Indicators Verified Low 0% DC-DC Converters Tested Medium 0% Fuse Protection Implemented / Verified High 0% Temp Sensor Power Solution Researched Low 0% Temp Sensor Power Solution Built and Installed Low 0% Temp Sensor Power Solution Tested Low 0% 2.11.1 2.11.2 2.11.3 2.11.4 2.11.5 2.11.6 2.11.7 2.11.8 2.11.9 Find DC-DC Converters Criteria for this milestone shall be 20% founding design, 10% if talked to designer, 60% if found converters, 10% if find spec list. (or if find that spec list doesn't exist) Create Power Budget Criteria for this milestone shall be 10% for obtaining each sub-team's power requirements/estimates at the beginning of the semester, 10% for producing the initial document, 10% for obtaining each sub-team's power requirements/estimates at the end of the semester, and 10% for having a document at the end of the year. A complete, up to date document at the end of the year will be worth 100%, regardless. Verify Battery Status Criteria for this milestone shall be 33% each for testing ability to charge, testing ability to discharge, and testing ability to hold charge. Verify Battery Indicators Criteria for this milestone shall be 25% each for seeing if the charge drain meter is accurate, and 25% each for fixing any problems. Test DC-DC Converters Criteria for this milestone shall be 25% no load testing of voltage, 25% testing at controlled current, and 50% testing on the robot itself. Fuse protection Criteria for this milestone shall be solely the installation of fuse protection on all subsystems. Equal weight (25%) will be given for each subsystem requiring power: Motors, Software, Motion Control, and Sensors. Research for Temp Sensor Power Solution Criteria for this milestone shall be 50% started research, 50% found an acceptable design. Built & Installed Temp Sensor Power Solution Criteria for this milestone shall be 50% agreed upon design with the Sensor Sub-Team, 20% parts ordered, 10% prototype built, 10% final version built, 10% parts installed. Test Temp Sensor Power Solution Criteria for this milestone shall be 50% tested and 50% working. 6

2.13 Statement of Work Below is the power sub-team's statement of work. 2.13.1 Problem Definition Objective: Decide what goals are for the semester Approach: (See sub-steps) Result: Project plan with attainable, specific goals 2.13.1.1 Find DC-DC Converters Objective: Find out if old boards exist or if must build new ones Approach: Search through storage boxes, talk to second semester members, talk to former members, pray. Result: Find board or know need to revise project plan 2.13.1.2 Determine DC-DC Converter Capabilities Objective: Determine max power producible to compare with power budget in order to determine if can use old DC-DC boards in design. Approach: Search through storage boxes & internet for documentation, talk to second semester members, talk to former members, pray. Result: Know power producible by boards. 2.13.1.3 Create Power Budget (Preliminary) Objective: Find out if old boards will provide sufficient power for new system or if need to add more power capability. Approach: E-mail/talk to all sub-teams to get estimated Max Amps (@specified voltages) and estimated Average Amps (@specified voltages). Overestimating is a good thing here. Result: A rough idea of what power requirements are. 2.13.2 Technology and Implementation Considerations and Selection If a new power system needs to be designed either for the whole robot or just for Sensors, there will be some technology and implementation considerations and selection. 2.13.2.1 DEPENDS ON PROBLEM DEFFINITION / STATUS OF POWER Objective: Approach: Result: 2.13.3 End-product Design If a new power system needs to be designed either for the whole robot or just for Sensors, there might be some end-product design. However, the power sub-team is very small this year and limited on engineer hour resources to the extent that an end design may not be possible. 2.13.3.1 DEPENDS ON PROBLEM DEFFINITION / STATUS OF POWER Objective: Approach: Result: 7

2.13.4 End-product Prototype Implementation If a new power system needs to be designed either for the whole robot or just for Sensors, there might be one or two prototypes created. However, the power sub-team is very small this year and limited on engineer hour resources to the extent that completing a prototype implementation may not be possible. 2.13.4.1 DEPENDS ON PROBLEM DEFFINITION / STATUS OF POWER Objective: Approach: Result: 2.13.5 End-Product Testing If the old boards work out, the power sub-team will verify the boards' output power capabilities and implement them into OSCAR's power system. If the old boards don't work out, then this step may be saved for a future sub-team in a future semester. 2.13.6 End-Product Documentation 2.13.6.1 Development of End-User Documentation Objective: Convey how to operate the power to OSCAR team members Approach: Describe common procedures in writing. Test instructions on someone unfamiliar with OSCAR s power system. Result: An instruction set with digital pictures, demonstrating how to perform essential functions with OSCAR s power system. 2.13.6.2 Development of Maintenance Support Documentation Objective: Convey to future power teams how the power system works. Approach: A system by system written description shall be created and tested on someone knowledgeable about OSCAR. Result: A manual with pictures, describing the various component of the power system and how they all interact. This includes details of any work that needs to be done to complete the system. 2.13.7 End-Product Demonstration Objective: Show industrial review panel that OSCAR is working again. Approach: Test beforehand, hook OSCAR s power up to DC, and let OSCAR do a demo program made by the other OSCAR sub-teams. Result: OSCAR does a simple demonstration (created by other OSCAR sub-teams) for the industrial review panel. 2.13.8 Project Reporting Objective: Document all steps of the project to ease future team s understanding of past work. Approach: Create documentation following specifications laid out in the senior design course packet. Result: A full set of documentation covering all necessary aspects of the project. 8

2.13.8.1 Project Plan Objective: Layout proposed plan for project completion. Approach: Produce project plan according to specifications in the senior design course packet. Result: A better understanding of necessary steps to see the project successfully through to completion. 2.13.8.2 Project Poster Objective: Produce a poster which clearly and briefly documents power sub-team s efforts and the expected project outcomes of work on power in OSCAR. Approach: Produce project poster according to specifications in the senior design course packet. Result: A poster that displays, succinctly, the efforts and expected outcomes of the project and the power sub-team s efforts. 2.13.8.3 Design Report Objective: Document the decisions and reasoning behind design of OSCAR s power systems. Approach: Produce design report according to specification in the senior design course packet. Result: A document which makes available the reasoning of the team members through their design process. 2.13.8.4 Status Report Objective: Inform the advisors of the overall progress of work on project OSCAR s power sub-system. Approach: Produce status report according to specifications in the senior design course packet. Result: A way for advisors and future team members to learn where the project currently stands and what needs to be completed. 2.13.8.5 Weekly Email Reporting Objective: Keep advisor abreast of issues encountered with OSCAR and the project on a weekly basis. Approach: Produce weekly status reports according to specifications in the senior design course packet: power sub-team leader will report to advisors via email on issues facing the team as well as solutions considered and other problems. Result: Both the advisor and the team will be kept apprised of problems and progress of project. This will facilitate finding solutions and avoiding delays. 9

3. Estimated Resource Requirements and Schedules Planned resource allocation and scheduling have been done. 3.1 Estimated Resource Requirement Planned resource allocation is outlined below: 3.1.1 Financial Financial expenditures for the power sub-team are listed in Table 3-1 below. Inability to find the DC-DC converters or the choosing of a completely separate power supply for Sensors could increase costs significantly. Table 3-1 Power sub-team financial budget Description Quantity Unit Price Total Poster fees 2 $25.00 $50.00 Total $50.00 3.1.2 Personnel Effort Having only two people, the power sub-team members will spend much of their time going to meetings and writing reports. The sub-team members will also spend a good portion of time installing and testing devices. See table 3.2 for details. Table 3-2 Power sub-team personnel effort budget ITEM Daniel Marquis Hong Nguyen Meetings (2hr/week/person)*(4 week/month)*(4 month/semester) 32 32 Search for documentation (in Town or call people) 8 5 Ordering parts 5 5 Physical installation and testing 10 15 Making report 10 5 Research 5 5 Total: 70 67 10

3.2 Schedules Below are some tables outlining the power sub-team s project schedule. Table 3-3 Power sub-team major tasks schedule Task From Day Month Day To Month Length of Time (total day) Provide Temp Power 21 9 23 11 45 Research testing circuit (DC/DC) Testing DC/DC circuit 21 9 30 9 26 10 30 10 25 23 Research testing circuit (Monitor Battery) Testing Monitor Battery 21 9 30 9 26 10 30 10 25 23 Provide Power 26 10 25 12 44 Table 3-4 Power sub-team deliverables schedule Deliverable From Day Month Day To Month Length of Time (total day) Email weekly 21 9 25 12 69 Class Presentation 21 10 21 11 30 Poster 21 9 21 10 30 Start Report 27 11 15 12 30 Status report to web Site 30 11 15 12 27 11

A tentative schedule to complete the tasks listed in table 3.4 is shown below, in figure 3.1. Figure 3-1 Power sub-team schedule of tasks Figure 3-1 Power sub-team schedule of tasks 12

A tentative schedule of deliverables listed in table 3.4 is shown below, in figure 3.2. Figure 3-2 Power sub-team schedule of deliverables Figure 3-2 Power sub-team schedule of deliverables 13

4. Project Team Information Contact information for various parties involved in the power sub-teams project are as follows: 4.1 Client information Iowa State University Department of Electrical and Computer Engineering 2215 Coover Ames, IA 50011 voice: (515) 294-2663 fax: (515) 294-3637 ece@ee.iastate.edu 4.2 Faculty advisor information Ralph Patterson III 326 Town Engineering Ames, IA 50011 voice: 515-294-2428 fax: 515-294-6760 repiii@iastate.edu 4.3 Team member information Daniel J. Marquis Electrical Engineering, French 4894 Helser Haber Ames, IA 50012 (515) 572-2819 dmarquis@iastate.edu Hong Viet Nguyen Electrical Engineering 1074 16th st Des Moines, IA (515) 243-0397 hongviet@iastate.edu 14

5. Closing Summary The efforts of this sub-team will be focused on supplying a working power system for OSCAR so that it can give demonstrations again. 15