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Proposed final projects

1. High speed processing of Conoscopic Holography signals

ABSTRACT

The Smart Sensor is a device that measures very accurately distances in the micro meter regime it is based on Conoscopic Holography technologies. Conoscopic is a unique implementation of a polarized light interference process, based on crystal optics. In the basic interference set-up, a light beam is projected onto a diffusive object. The beam creates a light point on a target, which via reflection disperses the light in all directions. A complete solid angle of the diffused light is analyzed. The measurement process corresponds to the retrieval of the distance of the light point from a fixed reference plane. As such, three-dimensional measurement of bodies are obtained using Conoscopic Holography technology with single digit micrometers accuracies.

A major sub system in the sensor is its SW/HW electronics. Beside the electronic interface to the outside world in terms of SW and HW along with power supplies the overall system architecture is based on a System On Chip (SOC). It relies on a single component performing all the necessary tasks to create measurements. Namely:

1. Communication with host PC

2. Communication dispatcher HW/SW

3. Timing control

4. HW algorithm calculations

5. SW algorithm calculations

The analog output signal of the light energy sensing device is sampled by the Processing Unit (PU) which is based on XILINX FPGA and goes through a rigorous signal conditioning, noise filtering, signal processing leading to a non precedence results in precision and accuracies of the distance measured.

Currently the device operates in a regime of a few KHZ sampling rate.

Proposed Project.

The main objective of the project is to come up with a proposed architecture including definition of the required components and devices for the SOC Unit (that includes PU and IO sub boards as today) in terms of HW/SW processing in order to increase the measurements rates up to 100KHZ??? While maintaining the required accuracies in a restricted and define volume.

In order to accomplish these goals the following steps are proposed:

1. Understanding the current SOC system including:

a. understanding the Opto -Physical technology

b. understanding the device signals characteristics and properties

c. signal processing methods used in the system (analog and digital)

d. Study the current technology being used ( FPGA, analog/digital interfaces to external components)

e. Communication to PC

2. Develop optimal architecture

a. In terms of speed and size

b. simulation of the architecture using real acquired data.

c. estimation of the expected accuracies and uncertainties in the results.

d. Proposed layout.

2. Merging and Decimation of clouds of points from a scanning system with multiple viewing angles.

In order to scan a 3-D image of a complex geometrical object one has to maneuver the sensing unit in various viewing angles. One solution implies the application of Polygon, a system of multiple mirrors mounted at different angles, on the single axis. This system provides a number of scanned object images taken from different angles (viewpoints).

In example, a polygon with 5 faces will yield a five sets of clouds each taken at different viewing angle that must be merged while taken into account overlaps.

A special algorithm of image merging must be develop taken into accounts various properties of the data characteristic to name a few: noisy points, low level signals, filtration of bad points, decimation of points, optimization method for choosing the points at the overlap section and develop criteria's, etc..

Since the scanning time and method is of the essence, one has to optimized the scanning mythology.

The works will be perform on a real system with real data and beside optimization of the data processing in terms of time an interactive display must be integrated into the package.

3. Dynamic Auto Focus System

In High power Laser based systems application there is a strenuous required to deliver maximum energy to a given point i.e. in laser welding applications. As such on must be able to measure dynamically with extreme accuracy the distance to the geometrical body. In other word, there is the need for an Auto-focus system using a remote sensing sensor that will enable to optimize the energy delivery at a given point at micometer precision.

In welding application for example the profile body moves along a given axis and its dynamic distance variation is measured in real time, processed and dynamically send control commands to the motors to move the laser head to precise position. In order to perform focus correction the position update should be optimized and some prediction calculation must be performed in terms of the geometrical characteristic of the body in order to comply with required update rates.

In these type of applications the process usually starts by reading a motor position from a controller. The position readout is send to a PC. Controller send position data in parallel to the distance measured by the high accuracy distance measuring sensor. An algorithm performs a comparison and a new position is define. The system sends a command to the motor to move the laser head to the right position.

It is required to develop, construct and test Algorithm SW and HW that will optimize the control process of the laser position in real time using System ON Chip (SOC FPGA - Xlinx) processor, controllers along with drivers and motors.

4. Software tool for optimization scanning configuration

Using optical Sensor with line scanner

In order to scan a 3-D image of a complex or a set of geometrical objects, one has to maneuver the sensing unit in various viewing angles. One solution implies the application of Polygon, a system of multiple mirrors mounted at different angles, on the single axis. This system provides a number of scanned object images taken from different angles (viewpoints).

In these types of systems on has to develop the strategy in terms of the scanning methodology, implying optimization of scanning mirrors frequency, how many viewing angles are sufficient to obtain the image, required optics, moving platforms and controls, etc.

The goal for such a type of system is to optimize the major parameters such as lateral distribution of the scan ( separation between lines) related to the object geometrical properties , angle coverage, precision, minimal scanning time, etc so as to obtain a fast 3D scanning system which is highly accurate, self calibrated with good reproducibility

The goal is to build a model and SW package for optimizing the 3D scanner performance. The model will be tested empirically on different geometrical bodies or objects configuration.

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