1. Performed by: Maria terushkin & Guy Ovadia Mony Orbach Instructor: Mony Orbach Cooperated with: Alex Bekker (EO Laboratory) המעבדה למערכות ספרתיות מהירות High speed digital systems laboratory הטכניון - מכון טכנולוגי לישראל הפקולטה להנדסת חשמל Technion - Israel institute of technology department of Electrical Engineering דו”ח סיכום פרויקט DDL controller: Diferential Delay Line controller סמסטר חורף 2006 1

2. Abstract המעבדה למערכות ספרתיות מהירות High speed digital systems laboratory 2 Our project’s goal was to implement a digital control system for the Differential Delay Line (DDL). The DDL is an OEM electro-optical component used to create a difference in travel path lengths of laser beams. Previously, the DDL was controlled manually – which caused severe instability, and made the operation of the device complicated and discontinuous. The extremely high resolution capability of the DDL was not fully realized. The project consists of the controller hardware that drives the motor inside the DDL, as well as convenient PC software with a Windows GUI. The hardware implements a closed –loop PID controller, a motor driver power stage, and USB communications with the PC. The main project requirements were to achieve the maximal positional accuracy theoretically possible for the DDL, to protect the DDL from moving beyond the limits of the safe travel range, and have no cumulative error. Converging to the required set-point should be as fast as possible while still meeting the above requirements. The implementation platform is a combination of an existing FPGA card from a previous project done in the laboratory, plus a small custom wire-wrapped board for the power stage and DDL interface. Several complications have emerged, resulting mainly from the non-linear properties of the DDL electro-mechanical stage (friction, gear backlash). Stable closed-loop control was achieved using several techniques to overcome these problems. The performance requirements of accuracy and minimal error were achieved and even exceeded. A command-line version of the software was developed to ease interfacing with existing test-equipment control software (Agilent VEE Pro). Integration of the controller with the instrumentation and control software at the Electro- Optics lab was successfully completed.

3. System description המעבדה למערכות ספרתיות מהירות High speed digital systems laboratory 3 Hardware Based on Altera Cyclone I USB communication using DLP PWM output Encoder + LS inputs Software PID control algorithm Serial communication protocol

4. Specification and Features המעבדה למערכות ספרתיות מהירות High speed digital systems laboratory 4 Steady state error: 1 encoder count Zero Cumulative positional error Convergence to set point: 3 sec max. End-of-travel safety limits in Hardware Setpoint detection feature opens the control loop after convergence Interactive Control from GUI application Automation support through command-line with Agilent VEE pro software

5. System Block Diagram המעבדה למערכות ספרתיות מהירות High speed digital systems laboratory 5 MMC wire-wrap Altera Cyclone transceiver H bridge HIP4020 Power Management Power Management DLP USB245M

6. FPGA Block Diagram המעבדה למערכות ספרתיות מהירות High speed digital systems laboratory 6 Synchronization Debouncing Filtering Of signals Position Decoding PID PWM Duty-cycle homing Limit Protection Communication Main Controller mux Control lines to all blocks