Disk Drive Servo System Design
and Simulation Tool

Why Purchase This Tool? 

This fully integrated design and simulation tool allows your designers to rapidly develop and optimize a complete disk drive servo system and directly observe the performance and complex interaction of mechanical, electrical, digital servo and adaptive system dynamics.

The user has direct visual access to the internal states of each of the interconnected and simultaneously operating electrical, mechanical and control/DSP portions of the system. Because it is based on the flexible, open architecture of MATLAB and SIMULINK, this tool allows designers to graphically explore a multitude of what if possibilities, tune performance and debug problems prior to or concurrent with prototype development.

Purchasing a mature product like this that has been developed by an recognized expert both in disk drive digital servo systems and dynamics modeling saves the time, frustration and considerable expense of attempting to doing it yourself. However, you have the freedom to easily change both the simulation model structure and parameters as you see fit.

Tool Benefits

• Rapid optimization of the complete head positioning system including mechanics, electronics and digital control.
• Rapid what if testing and optimization.
• Reduce risk and engineering expense by simulating and testing before committing to product development.
• Reduce time consuming and unnecessary mechanical changes.
• Reduce prototype testing time.
• Quickly evaluate performance with worst case component tolerances.
• Quickly and fairly compare competing control algorithms.
• Reduce seek time using advanced fast seek profile design tool.
• Improve both tracking accuracy and settling performance at high track densities and in presence of actuator friction.
• Improve operating shock and vibration robustness.
• Improve both quality and speed of runout correction using built-in high-performance runout adaptation.

Tool Features

• Tool meticulously integrates a virtual wish list of mechanical, electrical, digital servo and adaptive system dynamics.
• View the internal operation of the mechanical, electrical and digital control subsystems.
• Simulation also performs arbitrary length seeks in either direction, settling and track following operations utilizing a seek/settling profiles and deceleration anticipation.
• Actuator dynamics include bearing stiction, arm/head/coil resonant modes, nonlinear bias torque, power amplifier dynamics, motor electrodynamics, A/D and D/A quantization.
• Disturbances include repeatable and non-repeatable runout, bias and cable forces and a selection of industry standard external shock and vibration sources.
• Practical complete digital state estimators and compensators and design scripts included.

Application Areas

Sample Output

Here is what you would see on just two (of many) scopes displayed during a typical Seek/settle simulation. Other simulation modes include: Track follow, Runout adaptation and correction, Shock and vibration testing, Bandwidth adaptation, and Transconductance amplifier response with the closed loop plant.

A long seek on a 3.5" HDD with state-estimator based digital control.

Dr. Sidman is an independent engineering consultant with 25 years of practical industrial design experience. He is an expert in digital servo systems and disk drive head positioning servo control, with roles spanning product design, advanced development and applied research. He is the named inventor on 18 U.S. patents, author of many technical papers and received a Ph.D. from Stanford University in 1986. As Digital Equipment Corporation's top servo systems guru, Dr. Sidman was responsible for developing novel servomechanical technology for disk drives and headed the Storage Division's Servo-Mechanical Advanced Development Group.   The Adaptive Runout Correction System (ARCS) developed by Dr.  Sidman in 1977-78 is considered to be the first use of digital signal processing in a disk drive. Dr. Sidman also pioneered and demonstrated disk drive shock and vibration correction using an HDA mounted angular accelerometer and the use of high bandwidth microactuators in HDDs over ten years ago.  Dr. Sidman is a Senior Member of the IEEE and a Member of the ASME and has been a consultant to and Third Party Provider for The MathWorks since 1994. He founded his engineering consulting business in 1989 and is listed in Marquis Who'sWho in Science and Engineering 1998-1999.

Would you like an on-site, comprehensive and practical Short Course on Digital Servo Systems For Disk Drives?

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