CSA analyzes, designs and implements control systems for vibration reduction, precision motion, and other control for a wide variety of physical systems and processes. Quite often, the systems we control involve structural dynamics, and resonances, making certain types of traditional control impractical. Optical systems often require precision motion control and vibration suppression. Our engineering of control systems includes model development, control design, and physical implementation.

Control system development usually begins with models of physical systems. Ranging from active optics and steering mirrors to pneumatic actuators, vibration isolators and hexapod platforms, these models are derived from fundamental physics, other representations such as finite element models, or measured data. Matlab is one of our core tools, and we use custom libraries of Matlab and Simulink files to aid design. In some cases, we also develop these models for customer use, integrating control systems with specialized or general structures, optics or electromechanical models.

The types of physical systems CSA encounters require a range of control algorithms. Our engineers make use of existing algorithms and design methods, and develop new ones as required. Our expertise in feedback control systems includes classical and modern designs, SISO and MIMO, with incorporation of system identification, filtering, estimation and robust design. We also employ adaptive filtering and feedforward control techniques to a variety of systems. These powerful methods can be used independently or be combined with feedback control to achieve. Adaptive filter designs incorporate various structures and can be specialized effectively to reject single- and multiple tone disturbances.

Over the last several years, CSA has developed capabilities in feedforward control. The algorithms that originated in the signal processing world are often well suited to control of acoustic noise and other physical phenomena. CSA applies these algorithms to adaptive control systems, taking advantage of the processing power of digital signal processors (DSPs). We have used feedforward methods to create semi-autonomous and autonomous control for narrowband and broadband disturbances.

CSA's engineers are equally comfortable designing control systems using Matlab or other tools or implementing them on physical systems. In some cases, a CSA-designed algorithm will be implemented on customer platforms, and more often CSA supplies the hardware, firmware and/or software implementation. We realize control on a variety of platforms ranging from DSPs and FPGAs, to xPC, microcontrollers, and analog circuits. In each case we use the platform that best matches the requirements of the application and constraints of existing installations. Many of the control systems built by CSA use our own custom actuators and supporting electronics.

CSA's experience in active vibration control is considerable, and our engineers understand the appropriate algorithms and implementation methods. Control of hexapod and octopod positioning and suspension systems makes use of both local loops and global control. The intersection of motion and vibration control is a particular specialty.

One of the most important application areas for control at CSA is in optical systems. Fine positioning of components in multiple axes, jitter control, active optics, and wavefront control all benefit from our years of experience in analysis, design and implementation. Because metrics of performance are often related to fractions of wavelengths of light, fine motion and vibration control is required. We augment existing optical systems and provide add-on and new control capabilities to minimize jitter and improve overall performance.

DSP-Based and Embedded Control / Active/Adaptive Optics / Active Vibration Cancellation