3 Methods Applied

Utilizing Tegra II ULP GeForce GPU for

Integrated Machine Vision and Inverse Kinematics (IK)

on a Robotic (SCARA) Electric Vehicle Charging System

Kevin Leary and Mario Castaneda PowerHydrant LLC, Westwood Massachusetts

PowerHydrant®

1 Abstract PowerHydrant

® ELIMINATES ELECTRIC VEHICLE CHARGING INCONVENIENCE

Now anyone can charge an EV – multiple times a day, every day, rain or shine Patent pending PowerHydrant®: 1) Accelerates EV mass-market adoption, 2) improves EV charging safety & reliability, 3) ensures high efficiency charging, 4) targets residential and public places, 5) solves unaddressed EV charging problems. PowerHydrant will provide automated robotic charging solutions for both the residential setting and public spaces to provide EV owners a “park-and-forget” experience. A hardware module utilizing low cost vision guided robotics, J1772 compliant plug and communication interfaces will provide the automated connection whenever the vehicle is parked in a PowerHydrant enabled spot. Wireless and Inductive charger solutions fail at high power densities. The Nvidia Tegra II integrates a powerful mix of performance and features that are well-aligned to the application needs in PowerHydrant.

0 Takeaway The convergence of wireless tech, mobile chip sets and powerful software environments enabled the smartphone revolution. Applying these economies with the addition of powerful imaging and GPGPU capabilities enables a low-cost, high-performance, easily-engineered, embedded machine-to-machine (M2M) solution to an emergent problem in vehicle transportation.

2 ProblemOpportunitySolution

5 Performance Analysis

4 Implementation Highlights

Six Degrees-of-Freedom Selective Compliant Articulated Robot Arm (6 DOF SCARA) Active Degrees-of-Freedom • Three Vertical Axis Rotors (X,Y,Yaw) • One Vertical Linear (Z) Passive Degrees-of-Freedom • One Spring Loaded Angle (Pitch) • One Unconstrained (Roll)

Robotic Bollard OS and Control (Java)

Machine Vision

Algorithms (C++)

OpenGL ES 2.0 API Calls

OpenGL ES 2.0 API

Use GPGPU for Inverse Kinematics & Machine

Vision Acceleration

No Display or Touch

Inverse Kinematics

(C++) ARM &

OpenGL ES 2.0 API Calls

HD Camera: • Data sent to Main

Processing Board via CSI • No Focus Lens • 1920x1080– 29.97 fps

High Intensity IR LED and Photo Diode: • Illuminates Reflective

Leading Lights Target @ 7.4925Hz sync’d to frames

• IRDA

Primary Arm: Cast Aluminum • Main Processing Board (NVIDIA Tegra II)

• General Functional Control, AMR SW, Demand Response • Communications, Inverse Kinematics, Machine Vision

• 2 Rotating Steppers, 1 Linear Steppers w/ Power Chips • Mesh and Internet Gateway Comms: ZigBee, PLC, WIFI, 3G, 4G • AMR, Digital Metering, Shunt Resistors • Loud Speakers, Proximity Detectors, External Wire Antenna

Passive Bollard Base: Ductile Iron Pipe; {HVDC/Inverter}

Connector Arm and Head: Carbon Fiber • Digital Out HD Camera; Low Cost ARM M3; Lead Screw;

Secondary Arm: Cast Aluminum • 1 Rotating Steppers w/ Power Chips; Low Cost ARM M3

EV Charging is a Nuisance Wireless Charging Limits Max. Power Transfer

I. Automated Charger Connection is the Solution

II. Resonant Inductive Wireless Chargers are Appealing but they Exchange Efficiency for Charge-time. They also Suffer from Alignment Constraints

III. A Conductive Robotic Solution Delivers Convenience and Charger Performance – Short Charge-time @ High Efficiency

PowerHydrant® Supports 1-4 Vehicles at Home, Curb or Lot w/ Level I, II, or III Charging

Slicing and Decision-making

DG(x0..5)

6DOF Alignment Target Relative

to Camera

U.S. Provisional No. 61/246,524

U.S. Patent Application 12/888,532

International Patents PCT/US2010/-49907

Comb Filter Removes Background and Multi-scale Correlator Finds Leading-Lights Target

Used by Astronauts and Sea Captains, Leading Lights provide 6DOF Alignment

PowerHydrant Kinematic Diagram (Passive Degrees of Freedom Implied)

PowerHydrant Range of Motion Supports 14 Vehicles Mid-Front-of-Vehicle must enter the 60” (1.5 meter) Radius Cloud

• 1 or 2 Vehicles in a Garage or Driveway Scenario • 1 Vehicle for On-street Curb Scenario • Up to 4 Vehicles in a Parking Lot Scenario

oBalance Shear Vector Performance vs. Latency

oMost Elements of the IK Loop will can run on 1 GHz ARM Core

oMatrix Inversions and Jacobians run in Floating Point in GeForce via OpenGL API calls • Here Floating Point is Critical for Dynamic Range Support

oMachine Vision Comb Filter and 2D XCORR in Floating Point in

GeForce via OpenGL API calls • Here Floating Point helps Ease-of-Development

Android Platform allows for Embedability and Fast, Robust Development

oOuter-Loop Processes and Supervisory Control is installed as a Java Mobile-App at the Top Level

o The High Performance Demands of IK and Machine Vision are run at the Dalvik Virtual Machine Level

oPowerHydrant® Charger requires no display or touch input, but Graphics Processing Capability is key

o End-market Tablet Products, Rich 3rd party Infrastructure and global Android knowledge-base enable fast time-to-market and low development costs.

o Flexibility and Configurability in Supported M2M Communications Methods is Required G3-PLC or HomePlug GP Zigbee; Element14; 6LowPAN; ANT; WIFI GPS IrDA 3G UMTS WCDMA, 3G CDMA2000

o Android is an Ideal Platform for a Communications-centric Product

PowerHydrant is an Element of a Mesh-Computing System

Graphics Processing Repurposed to Accelerate Machine Vision & Matrix Ops

Integrated Machine Vision and Inverse Kinematics (IK) Signal Flow with Hardware Partitions

Key Rates/Data Sets MIPs Budget by FunctionVideo Frame Rate 29.97 Hz 2D XCORR 1.03 GFLOPs

Pixels/Frame 1920*1080 (2M) Comb Filter 297 MFLOPs

Pixel Rate 74.25 MHz Inverting Jacobian (QR Decomp) 0.13 MFLOPs

Core 6DOF Vector Size 6x1 6DOF Signal Flow 0.19 MFLOPs

Core Jacobian Size 6x6

6DOF Core Rate 29.97 Hz

Compute Resources Processing RatiosRaw ARM9 MIPs 2x1 GIPs Video-Image to IK Load Ratio 199:1

Allocated/Norm. ARM MIPs 500 MIPs

Raw GeForce GFLOPs 5.33 GFLOPs

Allocated GeForce GFLOPs 1.33 GFLOPs