Use or disclosure of document data is subject to the restrictions on the title pagePage 1 © 2014 Carnegie Robotics LLC. MARSUPIAL System/Subsystem Review Carnegie Robotics LLC. #10 40th Street Pittsburgh, PA Jared Raby Nico Gallardo Chris Griffin Sean Greenslade Wesly Rice

Use or disclosure of document data is subject to the restrictions on the title pagePage 2 © 2014 Carnegie Robotics LLC. Agenda Introduction Subsystem rework Subsystem Design  Tracks  Wireless Node Payload  Odometry  Electrical Systems Questions

Use or disclosure of document data is subject to the restrictions on the title pagePage 3 © 2014 Carnegie Robotics LLC. Introduction MARSUPIAL Tracked Rover for CRL Scope  Suspended Track System  Wireless Node Payload  Electrical Systems  Odometry Deliverables  Suspended Track System  Mesh Network Payload

Use or disclosure of document data is subject to the restrictions on the title pagePage 4 © 2014 Carnegie Robotics LLC. Subsystem Function Analysis ActionOptions/Steps to accomplish action/Functions Parameters needed complete actionParameter specificationsRisks associated with actionMitigation of risk Deploy Robot Person lifts the robotHandlesTwo on either side Weight consideration when lifting robot >1 person is used to lift the robot Mini-craneHoles for hooks/straps Hole must be at least 1.5" to fit standard strap hooks Unstable control of the robot while its hanging from straps connected to mini-crane. There needs to be 3 hook points in order to safely move the robot using a crane Drop from transportation platform Able to withstand impact Bumpers/suspension to absorb shock Module safety when being dropped Reinforced chassis and shock absorption Durable ChassisSafety to Personnel Needs to meet Military safety standard MIL 883E Ramp Braking system with manual release (parking brake) This can be in the form of a button that engages the brake when the button is not pressed and disengages when the button is pressed. Loose control of vehicle while it is descending from the ramp Manual brakes/emergency brakes Limited/no power to the motors -> ->"coasting function" or clutch Motor controller to control descent speedElmo motor controller Power-up Pre-inspectionVisual inspection of robotCheck off sheet must be completed Visual inspection is not adequate in identifying all malfunctions. Perform electrical self tests to identify other malfunctions Power-up logic Robot powerbb2590Battery shorts circuitsFuse to break circuit Switch on robot chassis (computer/logic systems) Key/toggle switch Self Tests Check all subsystem functionality NOT including drive system (motors) Establish communications w/ base station and payload All systems power-up Motor controller initialization and test Check motor control input range and controller configuration. Disengage Emergency Stop switch Emergency stop malfunction

Use or disclosure of document data is subject to the restrictions on the title pagePage 5 © 2014 Carnegie Robotics LLC. Drive Receive drive command Channel in control signals from CPU to microcontroller Serial/Ethernet/busNoise in the system Proper signal conditioning and isolation Interpret control signals and send PWM to motor controller Arduino/MSP430/other uC Control brakes intelligentlyArduino/MSP430/other uC Failsafe mode for loss of communications Detect loss of communication Run failsafe routine (deceleration) Wireless E-stop Packet loss Apply failsafe Power MotorsSupply power to motor controllers Battery rails Motors: ec60 maxoms Limited slip to turn Make sure motors are powerful enough to cause slipping DC/DC converters Monitor Power use/motor status Monitor speedOptical encoders Monitor power usageArduino/MSP430/other uC Monitor stall conditionsArduino/MSP430/other uC Navigation View obstacles LED lightingLighting malfunctionInfrared failsafe Camera subsystems Acquire environmental dataUltrasound/LIDAREnvironmental interference Analyze weather conditions before operation Track robot state Track motor odometry Wheel slippage causes false odometry readings Use GPS to confirm odometry readings Obtain accelerometer/gyro data Obtain GPS data Poor or unavailable GPS connectivity Overcome Stairs/Obstacles First Down step Manage tipping IMU data about system stateFaulty IMU readingsredundant IMU? Partial automation (autopilot)Unstable control loop Vigorous control loop testing Belt tension adjustment Electronic control of track tension Active suspension elements Situational limits/capslimited max speed up/down stairs Managing stairs/obstacles Track tread sufficient for step gripTrack slippage Overcoming obstacles Slopped track front Independent suspension elements Sealed/rugged undercarriage Rugged/durable tread material Sufficient power/torque to overcome obstacles The robot might get stuck or become inoperable without enough torque Situational awareness Slopped front for small obstacles ActionOptions/Steps to accomplish action/Functions Parameters needed complete actionParameter specificationsRisks associated with actionMitigation of risk

Use or disclosure of document data is subject to the restrictions on the title pagePage 6 © 2014 Carnegie Robotics LLC. Radio Transmitter Drop Radio Storage/Trans port Securely holds radios Droppable on commandDropping mechanism fails Reliable radio despenser design Charge radios Radio Use Determine drop necessity Radio strength/packet loss measurement Severe packet loss Intelligent radio dropping Manual activation Too many radios are dropped to reach desired range Intelligent radio dropping Distance-based drop (linear distance to last node) Situational drop (stair head, sharp turns, etc,) Too many radios are dropped to reach desired range Intelligent radio dropping Initialize radios before drop Radio power-up sequence & triggerRadio doesn't power up Routine maintanence of the radios Communications test before drop Radio requirements Fully charged/self containedCharging fails Check all radios for full charge before departing Standby/low-power mode while on robot Self-righting/omni-directional antenna(s) Low cost/semi-disposableUnit ends up being too expensive Thorough benchmarking for lowest cost solution Mesh protocol Status info for each node (batter, link, etc. Rugged/durable tread material Long battery lifeBattery failure Buy high quality, long lasting batteries ActionOptions/Steps to accomplish action/Functions Parameters needed complete action Parameter specificationsRisks associated with actionMitigation of risk

Use or disclosure of document data is subject to the restrictions on the title pagePage 7 © 2014 Carnegie Robotics LLC. Payload Use Attachment means Rails Electrical connections Power requirements Insufficient power is supplied to the system Thorough worst case testing regulated vs. unregulated power monitoring/limits Too much current is pulled from the battery and is critically damaged Real time power data and electrical limits Data connections Ethernet RS-485 Bays Physical size Payload is not the right size and doesn’t fit in the module bay Bay countNumber of possible modules Directions of expansion How payloads can extend outside the bounds of the bay Provisions for disjoint payload connections (e.g. rear radio deployment module) Software ProtocolsPhysical (Ethernet) & layer 2 (UDP) API's Systems that payloads can/cannot interact with or control Make computational power available to payloads Provide comms to operator ActionOptions/Steps to accomplish action/Functions Parameters needed complete action Parameter specificationsRisks associated with actionMitigation of risk

Use or disclosure of document data is subject to the restrictions on the title pagePage 8 © 2014 Carnegie Robotics LLC. Tracked Suspension System Suspension  Rugged against impact shock  Various environmental areas  Climb obstacles  Self Contained –IP Rated seals Drive-Train  Off the shelf motors  Meet speed and torque requirements –Simple gearing  Integrated electronics –Odometry Tracks  Proper materials –Coef of friction –Material stretch  Outdoor resistant –Chemical and physical ruggedness  Ease to install and remove

Use or disclosure of document data is subject to the restrictions on the title pagePage 9 © 2014 Carnegie Robotics LLC. Tracked Suspension System Drive-Train  Required Speed –Min of 5mph on level ground  Require Torque –To move 150 lbs of robot and payload  Off the Shelf Motor –Reduce overall price  Realistic Gear Train –8.0:1 – 12.0:1 –Planetary

Use or disclosure of document data is subject to the restrictions on the title pagePage 10 © 2014 Carnegie Robotics LLC. Tracked Suspension System

Use or disclosure of document data is subject to the restrictions on the title pagePage 11 © 2014 Carnegie Robotics LLC. Wireless Node Payload Droppable Node  OLinuXino – 575 MHz ARM Core –Running Arch Linux with B.A.T.M.A.N. wireless mesh protocol –USB Wi/Fi adapter –Buck converter –Li-on battery providing upwards of 6 hours of runtime Deployment System  Still in development

Use or disclosure of document data is subject to the restrictions on the title pagePage 12 © 2014 Carnegie Robotics LLC. Odometry Arduino with MPU-6050  6 axis IMU –3 axis accelerometer –3 axis gyro Magnetic encoders  Built into the Maxon EC-60 Brushless motor GPS  USB Receiver - Being Developed

Use or disclosure of document data is subject to the restrictions on the title pagePage 13 © 2014 Carnegie Robotics LLC. Electrical Systems

Use or disclosure of document data is subject to the restrictions on the title pagePage 14 © 2014 Carnegie Robotics LLC. Risks RiskSeverityOccurance ProbabilityMitigationOwner 1 Staffing/engineering ability41 Consultation with advisor/customer Scale back of scopeNico 2Budget51 Consultation with advisor/customer Scale back of scope Wes 3Machine setbacks31Plenty of lead timeWes 4Shipping setbacks31Plenty of lead timeNico 5Part setbacks31Plenty of lead timeJared 6 Incorrect Engineering Analysis23Thourough verification of analysis Per subsystem 7Ordering errors33Thourough verification of BOMNico 8 Catostrophic prototype failure51 Proof of concepts Small scale tests befor large scale testsChris 9Time constraints24 Consultation with advisor/customer Scale back of scopeJared 10Hardware failure34 Thorough design verification Spare componentsChris 11Mechanical failure34 Thorough design verification Spare componentsWes 12Software failure34 Thorough design verification Spare componentsSean 13Environmental factors15Review weather conditionsJared 14Technological limits31Review current technologiesSean

Use or disclosure of document data is subject to the restrictions on the title pagePage 15 © 2014 Carnegie Robotics LLC. Schedule

Use or disclosure of document data is subject to the restrictions on the title pagePage 16 © 2014 Carnegie Robotics LLC. Questions