oral report rev2
Post on 13-Jul-2015
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Advanced Robotic Mapper (ARM)Scott CrookECET 497Apr. 28, 2008A Robot that builds a map of its Environment!
PC Operator InterfaceBattery ChargerVehicleBlock Diagram
Position & Orientation Tracking BlockOptical Encoder Schematic/Hookup DiagramOptical Encoders
IR Device which reads dark and light areas of a wheel on the motor shaft.
Data is used to calculate displacement & orientation.
Clever method of interface with the main controller
Position & Orientation Tracking BlockDown CounterUp CounterCLKENENCLKA!ABBy using PSOC Timer blocks for up/down counters the need to use software interrupts is gone!The CPU can just check the count status of the timers to find the change since the last check.Quarter Resolution DecoderFrom Cypress App Note 2145
Position & Orientation Tracking BlockDigital Compass Schematic/Hookup DiagramsDigital Compass
Used to zero out accumulated error in orientation
Compass is a Honeywell HMC 6352
Battery ChargerMAX 713 Battery Charger SchematicHow it Works:2 modes (fast & trickle)Fast chargeRegulate VRsense to 250mV via Q2 duty cycleMonitor battery voltage to determine when to switch to trickle chargeTrickle chargeRegulate charge current to fast charge current/8 to top off battery.Ifast = 250mV/Rsense
Main Controller/LCDPSOCUser Modules model various HW (Timers, UART, LCD, etc)Control the Pinout of the final configuration for easier PCB layout.User modules have fairly well written interfaces so most of the low level code is done for you.
Software Overview - Main ControllerInitialize HWCheck for CommandsDo CommandedActionCommand Received?Check PositionYN
Software Overview OIInitializeWait for port selectWait for connection requestConnect to vehicleWait for command eventTranslate & Relay user command to vehicleUpdate MapMapping/Position update?Disconnect RequestDisconnectYYNN
Basic TestsWeight Requirements -> Scale TestWrobot = Wscott + robot - WscottTemperature Tolerance40 F -> Run Robot outside in weather colder than 40 deg (weather permitting) for 10 minutes or place robot in refrigerator for 10 minutes then exercise all HW while in fridge.80 F -> Turn up the heat to ~85 deg F and testLCD TestingLCD should show ARM run mode, Position, Orientation, and Bluetooth Connection Status
TestExpectedActualDateLCD ReportOKOK3-23-08Robot Weight< 10 lbs3 lbs2-5-08Temp 40 deg FHW OKHW OK2-16-08Temp 80 deg FHW OKHW OK2-16-08
Surface Detection TestARM was placed in a known environment with one surface more that 4 feet away from the vehicle. One wall must be at least 4ft from ARM. Mapping output is shown on the left versus dimensioned sketch of the area on the right.
Bidirectional Square Path TestThis test will determine how accurate the position and orientation tracking are.Robot travels a predetermined square path in both directions a set number of times.After each lap around the track the calculated position/orientation is compared to actual position/orientation and an error is computed
Bidirectional Square Path Test Results
Software Functionality TestsTest Method:Exercise all motion commands and data requests from OI
TypeNameOkDateCommandMotor DirY2-5-08CommandMotor SpeedY2-5-08CommandTurret AngleY2-5-08CommandCPU ResetY2-5-08RequestIR DataY2-5-08RequestCompass DataY2-5-08RequestARM InfoY2-5-08
Final Mapping Test Results
ItemCostPCB Costs$66Electromechanical$206.70Sensors$197.38Mechanical$254.31Power (Batteries, etc)$75.70Bluetooth$147.85Prototyping Misc$141.61LCDs$35.90Motor Driver ICs$73.45Other Parts (ICs, etc)$75.00Shipping$176.99Total$1450.89
Conclusions, Problems & RecommendationsOverall Summary:Mapping accuracy is good at startup but begins to degrade over time due to errors in position/orientation tracking.The time it takes the vehicle to complete a scan makes mapping while moving extremely difficult.
Problems:Accurate Position & Orientation tracking is extremely difficult due to mechanical issues.The compass reading is very unstable when the motors are operating.
Recommendations:Move the compass further away from the motors to reduce the magnetic interference from the motors.Characterizing the movement of the Servo would make the mapping even more accurate.