Observer-corrector control design for robots with destabilizing unmodeled dynamics

Robust Sliding Mode Control for Systems with Noise and Unmodeled Dynamics based on Uncertainty and Disturbance Estimation (UDE)

“…[13] proposed a patented observer corrector control system for system with unmodeled dynamics; deals with the first category. Canale and Milanese [14] gave necessary and sufficient condition on internal mode controllers for robust closed loop stability in presence of unmodeled dynamics and actuator saturation.…”

Advanced Control Techniques for Semiconductor and Flat Panel Display Substrate Handling Robots

“…The observer-corrector control strategy (Hosek 2001b; has been developed for applications where undesirable resonance conditions appear at frequencies above the minimum bandwidth necessary for required operation of the robot. In this approach, the system subject to control is viewed in terms of its dominant dynamics, which is essential to achieve required functionality, and the resonance properties associated with higher-order dynamic effects, which are imposed on the dominant dynamics and considered to be unnecessary and undesirable for proper operation.…”

“…A detailed description of the observer-corrector control strategy, including a complete report on the test implementation, can be found in Hosek (2001b) and . The strategy is subject to a patent protection .…”

Brooks Automation expands control capability of precision industrial robots

“…Implementation of low-pass filters and band-reject filters, an approach often adopted in the engineering practice to cope with structural resonances, is not effective for high-performance robots since low-pass filters introduce amplitude distortion and destabilizing phase lag, which deteriorates control performance, and bandreject filters are not suitable for applications where the resonance conditions shift during operation, change due to regular wear and tear, or vary because of production inconsistency. Brooks Automation has developed two innovative control concepts to The observer-corrector control strategy (Hosek et al, 2000(Hosek et al, , 2001Hosek, 2001a) has been developed for applications where undesirable resonance conditions appear at frequencies above the minimum bandwidth necessary for required operation of the robot. In this approach, the system subject to control is viewed in terms of its dominant dynamics, which is essential to achieve required functionality, and the resonance properties associated with higher-order dynamic effects, which are imposed on the dominant dynamics and considered to be unnecessary and undesirable for proper operation.…”

“…A detailed description of the observercorrector control strategy, including a complete report on the test implementation, can be found in Hosek et al (2000Hosek et al ( , 2001 and Hosek (2001a). The control strategy is widely used for Brooks Automation wafer-handling cluster-tool robots, including AquaTran 7 atmospheric robots and MagnaTran 7 vacuum robots with Leapfrog arms.…”