Robotic SensingRobotic SensingGuiding Undergraduate Research ProjectsGuiding Undergraduate Research Projects

AryeArye NehoraiNehoraiCenter for Sensor Signal and Information Processing (CSSIP)Center for Sensor Signal and Information Processing (CSSIP)

Signal Processing Innovations in Research and Information TechnoSignal Processing Innovations in Research and Information Technologieslogies ((SPIRIT) LabSPIRIT) Lab

January 2010January 2010

Department of Electrical & Systems Engineering

Department of Electrical & Systems Engineering

• We created a new multi-team undergraduate project entitled Robotic Sensing

• Students will take leadership roles in multi-semester projects

• Students will implement sensor systems for mobile robots that make autonomous decisions based on the sensed environment

• These systems include acoustic, chemical, RF electromagnetic, infra-red, and visual sensors

• The project is multidisciplinary, involving hardware, signal processing, imaging, control, communications, and computer interfaces

• It is led by the department chair, Dr. Arye Nehorai

ESE Launching Multi-team Robotic Sensing Project

Robotic Sensing – Multi-Team Project

Hardware Design Software/InterfaceDesign Algorithm Design

Physical/Chemical/BiologicalBackground

Transducer/Sensor Selection

Data Acquisition System(sampling rate and resolution)

Signal Conditioning(analog filter, signal amplifier)

Graphical User Interface (GUI)Design

Real-time Data ProcessingArquitectures

Statistical Signal ProcessingAlgorithms

Preprocessing Algorithms(Digital filters: FIR, IIR)

Graphical display of variablesof interest

User-defined System and Algorithms

parameters

Microcontroller

Actuators (motors)

Robotic Platform Central Processing

Com

mun

icat

ion

Chemical SensorsChemical Sensors

Acoustic Vector Acoustic Vector SensorsSensors

MicrophonesMicrophones Microcontroller

Servo Motor

Data Acquisition

Ultrasound SensorsUltrasound SensorsInfrared SensorsInfrared Sensors

Camera SensorsCamera Sensors

Robotic Sensing – Multi-Team Project

Robotic Sensing: Current Projects

Chemical SensorsChemical Sensors

Acoustic Vector SensorsAcoustic Vector Sensors

Chemical source position estimation (Joy Chiang)

Acoustic vector sensors for source location (Evan Nixon)

MicrophonesMicrophones

Adaptive source position estimation (Raphael Schwartz and Zachary Knudsen)

Microcontroller

Servo Motor

Data Acquisition

Advisor: Dr. Arye Nehorai

Ultrasound SensorsUltrasound Sensors

Real-time tracking (Andrew Weins)

Robotic Sensing: Adaptive Microphone ArraysRobotic Sensing: Adaptive Microphone Arrays

Current projects supervised by Professor Current projects supervised by Professor AryeArye NehoraiNehorai• Chase LaFont, Algorithms for sensing parameter adaptation, since summer 2009

• Raphael Schwartz and Zachary Knudsen, Data architectures for real-time acoustic source position estimation, since summer 2009

NTXPair of Motors Source Position Estimation

Sensing Acoustic FieldPair of Microphones + DAQ

Sensing parameter adaptation

Robotic Platform 1 Computer for Central Processing

Feedback

NTXPair of Motors

Sensing Acoustic FieldPair of Microphones + DAQ

Robotic Platform 2

NTXPair of Motors Source Position Estimation

Sensing Acoustic FieldPair of Microphones + DAQ

Sensing parameter adaptation

Robotic Platform 1 Computer for Central Processing

Feedback

NTXPair of Motors

Sensing Acoustic FieldPair of Microphones + DAQ

Robotic Platform 2

MicrophonesMicrocontroller

Servo Motor

Goal: To modify microphone array configuration adaptively for improving the performance in estimating acoustic source position using generalized cross- correlation algorithms.

Hardware DesignHardware Design

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Physical/Chemical/BiologicalBackground

Algorithm DesignAlgorithm Design

Cross Correlation D̂

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Physical/Chemical/Biological Background Statistical Signal Processing Algorithms

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Measurement Model

Time-delay estimation

Preprocessing Algorithms

• FIR filters

• IIR filters

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ˆcos 1−=θ

DOA estimation at each microphone

Algorithm Design (Cont.)Algorithm Design (Cont.)

Statistical Signal Processing Algorithms

Higher Resolution

Region of Ambiguity

Higher Resolution

Region of Ambiguity

Microphones pairs

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Xs = 1.949 Ys = 2.045 Error = 0.0680Xs = 2.323 Ys = 2.405 Error = 0.5180 Xs = 1.949 Ys = 1.944 Error = 0.0757

Hardware DesignHardware Design

Koss M-18 electret microphones DC Blocking Filter Diagram DAQ

Transducer/Sensor Selection Signal Conditioning Data Acquisition System

Microcontroller Actuators

NXT ARM7 Servomotor

Robotic Microphone array

Software/Interface DesignSoftware/Interface Design

Graphical display of variablesof interest

Graphical User Interface (GUI) Design

User-defined System and Algorithms

parametersReal-time Data Processing

Arquitectures

GUI using Matlab

Real time source location

Spectrogram

Estimated location

• Sensor array configuration

• Data acquisition system

• Preprocessing filters

• Cross-correlation algorithm

Robotic Microphone ArrayRobotic Microphone Array

Resolution

y

x

y

x

Error

PC

Statistical Signal Processing &Position Control

Algorithms

Measurements New array Configuration

Resolution

y

x

y

x

Error

PC

Statistical Signal Processing &Position Control

Algorithms

Measurements New array Configuration

Robotic Microphone ArrayRobotic Microphone Array

NTXPair of Motors Source Position Estimation

Sensing Acoustic FieldPair of Microphones + DAQ

Sensing parameter adaptation

Robotic Platform 1 Computer for Central Processing

Feedback

NTXPair of Motors

Sensing Acoustic FieldPair of Microphones + DAQ

Robotic Platform 2

Microphone Array DemonstrationMicrophone Array Demonstration

Demonstration at the WUSTL Undergraduate Research Symposium,Demonstration at the WUSTL Undergraduate Research Symposium,October 24October 24thth, 2009, 2009

Microphone Array Demonstration (Cont.)Microphone Array Demonstration (Cont.)

Demonstration at the WUSTL Undergraduate Research Symposium,Demonstration at the WUSTL Undergraduate Research Symposium,October 24October 24thth, 2009, 2009

Robotic Sensing: Acoustic Vector SensorsRobotic Sensing: Acoustic Vector Sensors

Current projects supervised by Professor Current projects supervised by Professor AryeArye NehoraiNehorai

• Ian Beil and Evan Nixon, Acoustic vector sensors for source location, since Fall 2009

Microphones

Goal: Estimate the position of an acoustic source using spatial and temporal measurements of pressure and particle acoustic field

Pressure sensor

Particle velocity sensor

Acoustic vector sensor (AVS)

Pressure sensor

Particle velocity sensor

Acoustic vector sensor (AVS) Measurement modelMeasurement model Acoustic source

AVS Far acoustic field

Acoustic sourceMeasurement modelMeasurement model Acoustic source

AVS Far acoustic field

Acoustic source

Euler equation

pressure at position r and time t

particle velocity at position r and time t

direction of particle velocity

speed of sound, Ambient pressure

Euler equation

pressure at position r and time t

particle velocity at position r and time t

direction of particle velocity

speed of sound, Ambient pressure

Robotic Sensing: Acoustic Vector Sensors (Cont.)Robotic Sensing: Acoustic Vector Sensors (Cont.)

Signal conditioner

DAQ

Array of AVS Capon Spectra

Signal conditioner

DAQ

Array of AVS Capon Spectra

Above: Diagram of experimental setup; Power distribution as a function of azimuth and elevation. The red arrow indicates the maximum spectral value.

Right: Experimental setup at SPIRIT LAB

Robotic Sensing: Current ProjectsRobotic Sensing: Current ProjectsAdvisor: Dr. Arye Nehorai

Chemical SensorsChemical Sensors

Acoustic Vector SensorsAcoustic Vector Sensors

MicrophonesMicrophones Microcontroller

Servo Motor

Data Acquisition

Ultrasound SensorsUltrasound SensorsInfrared SensorsInfrared Sensors

Camera SensorsCamera Sensors