/ Recent content on My digital brain Hugo -- gohugo.io en /paper/legnani12_new_isotr_decoup_paral_manip/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/legnani12_new_isotr_decoup_paral_manip/ Tags Stewart Platforms Reference (Legnani {\it et al.}, 2012) Author(s) Legnani, G., Fassi, I., Giberti, H., Cinquemani, S., & Tosi, D. Year 2012 Concepts of isotropy and decoupling for parallel manipulators isotropy: the kinetostatic properties (same applicable force, same possible velocity, same stiffness) are identical in all directions (e.g. cubic configuration for Stewart platform) decoupling: each DoF of the end effector can be controlled by a single actuator (not the case for the Stewart platform) Example of generated isotropic manipulator (not decoupled). /paper/fleming13_review_nanom_resol_posit_sensor/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/fleming13_review_nanom_resol_posit_sensor/ Tags Position Sensors Reference (Andrew Fleming, 2013) Author(s) Fleming, A. J. Year 2013 Define concise performance metric and provide expressions for errors sources (non-linearity, drift, noise) Review current position sensor technologies and compare their performance Sensor Characteristics Calibration and nonlinearity Usually quoted as a percentage of the fill-scale range (FSR): \begin{equation} \text{mapping error (%)} = \pm 100 \frac{\max{}|e_m(v)|}{\text{FSR}} \end{equation} With \(e_m(v)\) is the mapping error. /paper/preumont07_six_axis_singl_stage_activ/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/preumont07_six_axis_singl_stage_activ/ Tags Vibration Isolation, Stewart Platforms, Flexible Joints Reference (Preumont {\it et al.}, 2007) Author(s) Preumont, A., Horodinca, M., Romanescu, I., Marneffe, B. d., Avraam, M., Deraemaeker, A., Bossens, F., … Year 2007 Summary: Cubic Stewart platform (Figure 3) Provides uniform control capability Uniform stiffness in all directions minimizes the cross-coupling among actuators and sensors of different legs Flexible joints (Figure 2) Piezoelectric force sensors Voice coil actuators Decentralized feedback control approach for vibration isolation Effect of parasitic stiffness of the flexible joints on the IFF performance (Figure 1) The Stewart platform has 6 suspension modes at different frequencies. /paper/spanos95_soft_activ_vibrat_isolat/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/spanos95_soft_activ_vibrat_isolat/ Tags Stewart Platforms, Vibration Isolation Reference (Spanos {\it et al.}, 1995) Author(s) Spanos, J., Rahman, Z., & Blackwood, G. Year 1995 Stewart Platform (Figure 1): Voice Coil Flexible joints (cross-blades) Force Sensors Cubic Configuration Figure 1: Stewart Platform Total mass of the paylaod: 30kg Center of gravity is 9cm above the geometry center of the mount (cube’s center?). Limitation of the Decentralized Force Feedback: /paper/devasia07_survey_contr_issues_nanop/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/devasia07_survey_contr_issues_nanop/ Tags : Reference (Devasia {\it et al.}, 2007) Author(s) Devasia, S., Eleftheriou, E., & Moheimani, S. R. Year 2007 Talks about Scanning Tunneling Microscope (STM) and Scanning Probe Microscope (SPM) Piezoelectric actuators: Creep, Hysteresis, Vibrations, Modeling errors Interesting analysis about Bandwidth-Precision-Range tradeoffs Control approaches for piezoelectric actuators: feedforward, Feedback, Iterative, Sensorless controls Figure 1: Tradeoffs between bandwidth, precision and range Bibliography Devasia, S. /zettels/active_damping/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/active_damping/ Tags : <./biblio/references.bib> Backlinks Active isolation and damping of vibrations via stewart platform Active damping based on decoupled collocated control /paper/holterman05_activ_dampin_based_decoup_colloc_contr/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/holterman05_activ_dampin_based_decoup_colloc_contr/ Tags Active Damping Reference (Holterman & deVries, 2005) Author(s) Holterman, J., & deVries, T. Year 2005 Bibliography Holterman, J., & deVries, T., Active damping based on decoupled collocated control, IEEE/ASME Transactions on Mechatronics, 10(2), 135–145 (2005). http://dx.doi.org/10.1109/tmech.2005.844702 ↩ /paper/hanieh03_activ_stewar/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/hanieh03_activ_stewar/ Tags Stewart Platforms, Vibration Isolation, Active Damping Reference @phdthesis{hanieh03_activ_stewar, author = {Hanieh, Ahmed Abu}, school = {Universit{'e} Libre de Bruxelles, Brussels, Belgium}, title = {Active isolation and damping of vibrations via Stewart platform}, year = 2003, tags = {parallel robot}, } Author(s) Hanieh, A. A. Year 2003 Bibliography Hanieh, A. A., Active isolation and damping of vibrations via stewart platform (Doctoral dissertation) (2003). Universit{'e} Libre de Bruxelles, Brussels, Belgium, . /paper/alkhatib03_activ_struc_vibrat_contr/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/alkhatib03_activ_struc_vibrat_contr/ Tags : Reference (Rabih Alkhatib & Golnaraghi, 2003) Author(s) Alkhatib, R., & Golnaraghi, M. F. Year 2003 Process of designing an active vibration control system Analyze the structure to be controled Obtain an idealized mathematical model with FEM or experimental modal analysis Reduce the model order is necessary Analyze the resulting model: dynamics properties, types of disturbances, … Quantify sensors and actuators requirements. Decide on their types and location Analyze the impact of the sensors and actuators on the overall dynamic characteristics Specify performance criteria and stability tradeoffs Device of the type of control algorythm to be employed and design a controller to meet the specifications Simulate the resulting controlled system on a computer If the controller does not meet the requirements, adjust the specifications or modify the type of controller Choose hardware and software and integrate the components on a pilot plant Formulate experiments and perform system identification and model updating Implement controller and carry out system test to evaluate the performance Feedback control Active damping The objective is to reduce the resonance peaks of the closed loop transfer function. /zettels/actuators/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/actuators/ Tags : How to choose the correct actuator for my application? For vibration isolation: In (Shingo Ito & Georg Schitter, 2016), the effect of the actuator stiffness on the attainable vibration isolation is studied (Notes) Piezoelectric Suppliers Links Cedrat link PI link Piezo System link Noliac link A model of a multi-layer monolithic piezoelectric stack actuator is described in (Fleming, 2010) (Notes). /paper/oomen18_advan_motion_contr_precis_mechat/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/oomen18_advan_motion_contr_precis_mechat/ Tags Motion Control Reference (Tom Oomen, 2018) Author(s) Oomen, T. Year 2018 Figure 1: Envisaged developments in motion systems. In traditional motion systems, the control bandwidth takes place in the rigid-body region. In the next generation systemes, flexible dynamics are foreseen to occur within the control bandwidth. Bibliography Oomen, T., Advanced motion control for precision mechatronics: control, identification, and learning of complex systems, IEEJ Journal of Industry Applications, 7(2), 127–140 (2018). /paper/saxena12_advan_inter_model_contr_techn/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/saxena12_advan_inter_model_contr_techn/ Tags Complementary Filters Reference (Sahaj Saxena & YogeshV Hote, 2012) Author(s) Saxena, S., & Hote, Y. Year 2012 Proposed Filter \(F(s)\) \begin{align*} F(s) &= \frac{1}{(\lambda s + 1)^n} \\\ F(s) &= \frac{n \lambda + 1}{(\lambda s + 1)^n} \end{align*} Internal Model Control Central concept in IMC: control can be acheive only if the control system involves, either implicitly or explicitly, some representation of the process to be controlled. /paper/poel10_explor_activ_hard_mount_vibrat/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/poel10_explor_activ_hard_mount_vibrat/ Tags Vibration Isolation Reference @phdthesis{poel10_explor_activ_hard_mount_vibrat, author = {van der Poel, Gerrit Wijnand}, doi = {10.3990/1.9789036530163}, isbn = {978-90-365-3016-3}, school = {University of Twente}, title = {An Exploration of Active Hard Mount Vibration Isolation for Precision Equipment}, url = {https://doi.org/10.3990/1.9789036530163}, year = 2010, year = 2010, tags = {parallel robot}, } Author(s) van der Poel, G. W. Year 2010 Bibliography van der Poel, G. W., An exploration of active hard mount vibration isolation for precision equipment (Doctoral dissertation) (2010). /paper/holler12_instr_x_ray_nano_imagin/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/holler12_instr_x_ray_nano_imagin/ Tags Nano Active Stabilization System, Positioning Stations Reference (Holler {\it et al.}, 2012) Author(s) Holler, M., Raabe, J., Diaz, A., Guizar-Sicairos, M., Quitmann, C., Menzel, A., & Bunk, O. Year 2012 Instrument similar to the NASS. Obtain position stability of 10nm (standard deviation). Figure 1: Schematic of the tomography setup Limited resolution due to instrumentation: The resolution of ptychographic tomography remains above 100nm due to instabilities and drifts of the scanning systems. /paper/geng95_intel_contr_system_multip_degree/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/geng95_intel_contr_system_multip_degree/ Tags Stewart Platforms, Vibration Isolation Reference (Jason Geng {\it et al.}, 1995) Author(s) Geng, Z. J., Pan, G. G., Haynes, L. S., Wada, B. K., & Garba, J. A. Year 1995 Figure 1: Local force feedback and adaptive acceleration feedback for active isolation Bibliography Geng, Z. J., Pan, G. G., Haynes, L. S., Wada, B. K., & Garba, J. A., An intelligent control system for multiple degree-of-freedom vibration isolation, Journal of Intelligent Material Systems and Structures, 6(6), 787–800 (1995). /paper/wang12_autom_marker_full_field_hard/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/wang12_autom_marker_full_field_hard/ Tags Nano Active Stabilization System Reference (Jun Wang {\it et al.}, 2012) Author(s) Wang, J., Chen, Y. K., Yuan, Q., Tkachuk, A., Erdonmez, C., Hornberger, B., & Feser, M. Year 2012 Introduction of Markers: That limits the type of samples that is studied There is a need for markerless nano-tomography => the key requirement is the precision and stability of the positioning stages. Passive rotational run-out error system: It uses calibrated metrology disc and capacitive sensors /book/leach18_basic_precis_engin_edition/ Mon, 01 Jan 0001 00:00:00 +0000 /book/leach18_basic_precis_engin_edition/ Tags Precision Engineering Reference (Richard Leach & Stuart Smith, 2018) Author(s) Leach, R., & Smith, S. T. Year 2018 Bibliography Leach, R., & Smith, S. T., Basics of precision engineering - 1st edition (2018), : CRC Press. ↩ /paper/ito16_compar_class_high_precis_actuat/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/ito16_compar_class_high_precis_actuat/ Tags Vibration Isolation, Actuators Reference (Shingo Ito & Georg Schitter, 2016) Author(s) Ito, S., & Schitter, G. Year 2016 Classification of high-precision actuators Table 1: Zero/Low and High stiffness actuators Categories Pros Cons Zero stiffness No vibration transmission Large and Heavy Low stiffness High vibration isolation Typically for low load High Stiffness High control bandwidth High vibration transmission Time Delay of Piezoelectric Electronics In this paper, the piezoelectric actuator/electronics adds a time delay which is much higher than the time delay added by the voice coil/electronics. /zettels/complementary_filters/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/complementary_filters/ Tags : <./biblio/references.bib> Backlinks Advances in internal model control technique: a review and future prospects /websites/control_bootcamp/ Mon, 01 Jan 0001 00:00:00 +0000 /websites/control_bootcamp/ Tags : https://www.youtube.com/playlist?list=PLMrJAkhIeNNR20Mz-VpzgfQs5zrYi085m Overview Linear Systems Stability and Eigenvalues Linearizing Around a Fixed Point Controllability Controllability, Reachability, and Eigenvalue Placement Controllability and the Discrete-Time Impulse Response Degrees of Controllability and Gramians Controllability and the PBH Test Cayley-Hamilton Theorem Reachability and Controllability with Cayley-Hamilton Inverted Pendulum on a Cart Eigenvalue Placement for the Inverted Pendulum on a Cart Linear Quadratic Regulator (LQR) Control for the Inverted Pendulum on a Cart Motivation for Full-State Estimation Observability Full-State Estimation Kalman Filter Observability Example in Matlab Observability Example in Matlab (Part 2) Kalman Filter Example in Matlab Linear Quadratic Gaussian (LQG) LQG Example in Matlab Introduction to Robust Control Three Equivalent Representations of Linear Systems Example Frequency Response (Bode Plot) for Spring-Mass-Damper Laplace Transforms and the Transfer Function Benefits of Feedback on Cruise Control Example Benefits of Feedback on Cruise Control Example (Part 2) Cruise Control Example with Proportional-Integral (PI) control Sensitivity and Complementary Sensitivity Sensitivity and Complementary Sensitivity (Part 2) Loop shaping Loop Shaping Example for Cruise Control Sensitivity and Robustness Limitations on Robustness Cautionary Tale About Inverting the Plant Dynamics Control systems with non-minimum phase dynamics <. /paper/bryson93_contr_spacec_aircr/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/bryson93_contr_spacec_aircr/ Tags HAC-HAC Reference (Bryson, 1993) Author(s) Bryson, A. E. Year 1993 9.2.3 Roll-Off Filters Synthesizing control logic using only one vibration mode means we are consciously neglecting the higher-order vibration modes. When doing this, it is a good idea to insert “roll-off” into the control logic, so that the loop-transfer gain decreases rapidly with frequency beyond the control bandwidth. This reduces the possibility of destabilizing the unmodelled higher frequency dynamics ("spillover"). /zettels/cubic_architecture/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/cubic_architecture/ Tags : <./biblio/references.bib> Backlinks Sensors and control of a space-based six-axis vibration isolation system Dynamic modeling and decoupled control of a flexible stewart platform for vibration isolation Simultaneous, fault-tolerant vibration isolation and pointing control of flexure jointed hexapods /websites/data_driven_dynamical_systems_with_machine_learning/ Mon, 01 Jan 0001 00:00:00 +0000 /websites/data_driven_dynamical_systems_with_machine_learning/ Tags : Data-Driven Control Overview Challenges With modern control (LQR, LQG, H-Infinity), we work with linear system (or linearized systems) and we develop a control law that minimize some cost function. Challenging systems where modern control is not efficient: Non-linear systems System with unknown dynamics High dimensional systems Limited measurements or control inputs For these kinds of systems, data-driven control seems to be a good alternative. What is control? /paper/tang18_decen_vibrat_contr_voice_coil/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/tang18_decen_vibrat_contr_voice_coil/ Tags Stewart Platforms Reference (Jie Tang {\it et al.}, 2018) Author(s) Tang, J., Cao, D., & Yu, T. Year 2018 Bibliography Tang, J., Cao, D., & Yu, T., Decentralized vibration control of a voice coil motor-based stewart parallel mechanism: simulation and experiments, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 233(1), 132–145 (2018). http://dx.doi.org/10.1177/0954406218756941 ↩ /paper/schellekens98_desig_precis/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/schellekens98_desig_precis/ Tags Precision Engineering Reference (Schellekens {\it et al.}, 1998) Author(s) Schellekens, P., Rosielle, N., Vermeulen, H., Vermeulen, M., Wetzels, S., & Pril, W. Year 1998 Bibliography Schellekens, P., Rosielle, N., Vermeulen, H., Vermeulen, M., Wetzels, S., & Pril, W., Design for precision: current status and trends, Cirp Annals, (2), 557–586 (1998). http://dx.doi.org/10.1016/s0007-8506(07)63243-0 ↩ /book/fleming14_desig_model_contr_nanop_system/ Mon, 01 Jan 0001 00:00:00 +0000 /book/fleming14_desig_model_contr_nanop_system/ Tags : Reference (Andrew Fleming & Kam Leang, 2014) Author(s) Fleming, A. J., & Leang, K. K. Year 2014 Bibliography Fleming, A. J., & Leang, K. K., Design, modeling and control of nanopositioning systems (2014), : Springer International Publishing. ↩ /paper/yang19_dynam_model_decoup_contr_flexib/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/yang19_dynam_model_decoup_contr_flexib/ Tags Stewart Platforms, Vibration Isolation, Flexible Joints, Cubic Architecture Reference (Yang {\it et al.}, 2019) Author(s) Yang, X., Wu, H., Chen, B., Kang, S., & Cheng, S. Year 2019 Discusses: flexible-rigid model of Stewart platform the impact of joint stiffness is compensated using a displacement sensor and a force sensor then the MIMO system is decoupled in modal space and 6 SISO controllers are applied for vibration isolation using force sensors The joint stiffness impose a limitation on the control performance using force sensors as it adds a zero at low frequency in the dynamics. /paper/jiao18_dynam_model_exper_analy_stewar/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/jiao18_dynam_model_exper_analy_stewar/ Tags Stewart Platforms, Flexible Joints Reference (Jian Jiao {\it et al.}, 2018) Author(s) Jiao, J., Wu, Y., Yu, K., & Zhao, R. Year 2018 Bibliography Jiao, J., Wu, Y., Yu, K., & Zhao, R., Dynamic modeling and experimental analyses of stewart platform with flexible hinges, Journal of Vibration and Control, 25(1), 151–171 (2018). http://dx.doi.org/10.1177/1077546318772474 ↩ /zettels/electronics/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/electronics/ Tags : <./biblio/references.bib> Backlinks The art of electronics - third edition /paper/fleming12_estim/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/fleming12_estim/ Tags : Reference (Andrew Fleming, 2012) Author(s) Fleming, A. J. Year 2012 Bibliography Fleming, A. J., Estimating the resolution of nanopositioning systems from frequency domain data, In , 2012 IEEE International Conference on Robotics and Automation (pp. ) (2012). : . ↩ /zettels/flexible_joints/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/flexible_joints/ Tags : <./biblio/references.bib> Backlinks A six-axis single-stage active vibration isolator based on stewart platform Nanometre-cutting machine using a stewart-platform parallel mechanism Dynamic modeling and experimental analyses of stewart platform with flexible hinges Dynamic modeling and decoupled control of a flexible stewart platform for vibration isolation Simultaneous, fault-tolerant vibration isolation and pointing control of flexure jointed hexapods Investigation on active vibration isolation of a stewart platform with piezoelectric actuators Identification and decoupling control of flexure jointed hexapods /paper/preumont02_force_feedb_versus_accel_feedb/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/preumont02_force_feedb_versus_accel_feedb/ Tags Vibration Isolation Reference (Preumont {\it et al.}, 2002) Author(s) Preumont, A., A. Francois, Bossens, F., & Abu-Hanieh, A. Year 2002 Summary: Compares the force feedback and acceleration feedback for active damping The use of a force sensor always give alternating poles and zeros in the open-loop transfer function between for force actuator and the force sensor which guarantees the stability of the closed loop Acceleration feedback produces alternating poles and zeros only when the flexible structure is stiff compared to the isolation system The force applied to a rigid body is proportional to its acceleration, thus sensing the total interface force gives a measured of the absolute acceleration of the solid body. /zettels/force_sensors/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/force_sensors/ Tags : Suppliers PCB link Dynamics and Noise of a piezoelectric force sensor An analysis the dynamics and noise of a piezoelectric force sensor is done in (Fleming, 2010) (Notes). Bibliography Fleming, A., Nanopositioning system with force feedback for high-performance tracking and vibration control, IEEE/ASME Transactions on Mechatronics, 15(3), 433–447 (2010). http://dx.doi.org/10.1109/tmech.2009.2028422 ↩ /book/leach14_fundam_princ_engin_nanom/ Mon, 01 Jan 0001 00:00:00 +0000 /book/leach14_fundam_princ_engin_nanom/ Tags Metrology Reference (Richard Leach, 2014) Author(s) Leach, R. Year 2014 Measurement of angles Unit: radian for plane angle steradian for solid angle \(1 rad \approx 55.3deg\) Instrument principles: subdivision: index tacle, angular gratings, polygons, … ratio of two lengths: angular interferometers, sin cars, small angle generators, … autocollimators with a flat mirror Sources of error in displacement interferometry Two error sources: error sources that are proportional to the displacement being measured \(L\): cumulative errors error sources that are independent of the displacement being measured: non-cumulative errors Thermal expansion of the metrology frame Deadpath length Deadpath length, \(d\), is defined as the difference in distance in air between the reference and measurement reflectors and the beam splitter when the interferometer measurement is initiated. /paper/bibel92_guidel_h/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/bibel92_guidel_h/ Tags H Infinity Control Reference (Bibel & Malyevac, 1992) Author(s) Bibel, J. E., & Malyevac, D. S. Year 1992 Properties of feedback control Figure 1: Control System Diagram From the figure 1, we have: \begin{align*} y(s) &= T(s) r(s) + S(s) d(s) - T(s) n(s)\\\ e(s) &= S(s) r(s) - S(s) d(s) - S(s) n(s)\\\ u(s) &= S(s)K(s) r(s) - S(s)K(s) d(s) - S(s)K(s) n(s) \end{align*} /zettels/h_infinity_control/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/h_infinity_control/ Tags : Nice Citations From Rosenbrock, H. H. (1974). Computer-Aided Control System Design, Academic Press, New York: Solutions are constrained by so many requirements that it is virtually impossible to list them all. The designer finds himself threading a maze of such requirements, attempting to reconcile conflicting demands of cost, performance, easy maintenance, and so on. A good design usually has strong aesthetic appeal to those who are competent in the subject. /zettels/hac_hac/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/hac_hac/ Tags : High-Authority Control/Low-Authority Control From (Andre Preumont, 2018): The HAC/LAC approach consist of combining the two approached in a dual-loop control as shown in Figure 1. The inner loop uses a set of collocated actuator/sensor pairs for decentralized active damping with guaranteed stability ; the outer loop consists of a non-collocated HAC based on a model of the actively damped structure. This approach has the following advantages: The active damping extends outside the bandwidth of the HAC and reduces the settling time of the modes which are outsite the bandwidth The active damping makes it easier to gain-stabilize the modes outside the bandwidth of the output loop (improved gain margin) The larger damping of the modes within the controller bandwidth makes them more robust to the parmetric uncertainty (improved phase margin) /paper/chen00_ident_decoup_contr_flexur_joint_hexap/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/chen00_ident_decoup_contr_flexur_joint_hexap/ Tags Stewart Platforms, Flexible Joints Reference (Yixin Chen & McInroy, 2000) Author(s) Chen, Y., & McInroy, J. Year 2000 Bibliography Chen, Y., & McInroy, J., Identification and decoupling control of flexure jointed hexapods, In , Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065) (pp. ) (2000). : . ↩ /paper/garg07_implem_chall_multiv_contr/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/garg07_implem_chall_multiv_contr/ Tags Multivariable Control Reference (Sanjay Garg, 2007) Author(s) Garg, S. Year 2007 Discusses: When to use multivariable control and when not to? Two major issues with implementing multivariable control: gain scheduling and integrator wind up protection Inline simple gain and phase margin measured for SISO, “robustness” determination of multivariable control requires complex analyses using singular value techniques and Monte Carlo simulations. When to use multivariable control: /zettels/inertial_sensors/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/inertial_sensors/ Tags Position Sensors Reviews (Collette {\it et al.}, 2012) Accelerometers Micromega Dynamics link MMF link PCB link Wireless Accelerometers https://micromega-dynamics.com/products/recovib/miniature-vibration-recorder/ Figure 1: Characteristics of commercially available accelerometers (Collette {it et al.}, 2011) Geophones Sercel link Wilcoxon link /paper/stankevic17_inter_charac_rotat_stages_x_ray_nanot/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/stankevic17_inter_charac_rotat_stages_x_ray_nanot/ Tags Nano Active Stabilization System, Positioning Stations Reference (Tomas Stankevic {\it et al.}, 2017) Author(s) Stankevic, T., Engblom, C., Langlois, F., Alves, F., Lestrade, A., Jobert, N., Cauchon, G., … Year 2017 Similar Station than the NASS Similar Metrology with fiber based interferometers and cylindrical reference mirror Figure 1: Positioning Station Thermal expansion: Stabilized down to \(5mK/h\) using passive water flow through the baseplate below the sample stage and in the interferometry reference frame. /paper/wang16_inves_activ_vibrat_isolat_stewar/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/wang16_inves_activ_vibrat_isolat_stewar/ Tags Stewart Platforms, Vibration Isolation, Flexible Joints Reference (Wang {\it et al.}, 2016) Author(s) Wang, C., Xie, X., Chen, Y., & Zhang, Z. Year 2016 Model of the Stewart platform: Struts are treated as flexible beams Payload and the base are treated as flexible plates The FRF synthesis method permits to derive FRFs of the Stewart platform The model is compared with a Finite Element model and is shown to give the same results. /paper/gao15_measur_techn_precis_posit/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/gao15_measur_techn_precis_posit/ Tags Position Sensors Reference (Gao {\it et al.}, 2015) Author(s) Gao, W., Kim, S., Bosse, H., Haitjema, H., Chen, Y., Lu, X., Knapp, W., … Year 2015 Bibliography Gao, W., Kim, S., Bosse, H., Haitjema, H., Chen, Y., Lu, X., Knapp, W., …, Measurement technologies for precision positioning, CIRP Annals, 64(2), 773–796 (2015). http://dx.doi.org/10.1016/j.cirp.2015.05.009 ↩ /zettels/metrology/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/metrology/ Tags : <./biblio/references.bib> Backlinks Fundamental principles of engineering nanometrology /book/ewins00_modal/ Mon, 01 Jan 0001 00:00:00 +0000 /book/ewins00_modal/ Tags System Identification, Reference Books Reference (Ewins, 2000) Author(s) Ewins, D. Year 2000 Overview Introduction to Modal Testing The major objectives of modal testing are: Determining the nature and extent of vibration response levels in operation Verifying theoretical models and predictions of the vibrations Measurement of the essential materials properties under dynamic loading, such as damping capacity, friction and fatigue endurance For many applications, vibrations is directly related to performance and it is important that the vibration levels are anticipated and brought under satisfactory control. /book/du10_model_contr_vibrat_mechan_system/ Mon, 01 Jan 0001 00:00:00 +0000 /book/du10_model_contr_vibrat_mechan_system/ Tags Stewart Platforms, Vibration Isolation Reference (Chunling Du & Lihua Xie, 2010) Author(s) Du, C., & Xie, L. Year 2010 Read Chapter 1 and 3. Bibliography Du, C., & Xie, L., Modeling and control of vibration in mechanical systems (2010), : CRC Press. ↩ /zettels/motion_control/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/motion_control/ Tags : <./biblio/references.bib> Backlinks Advanced motion control for precision mechatronics: control, identification, and learning of complex systems /book/du19_multi_actuat_system_contr/ Mon, 01 Jan 0001 00:00:00 +0000 /book/du19_multi_actuat_system_contr/ Tags : Reference (Chunling Du & Chee Khiang Pang, 2019) Author(s) Du, C., & Pang, C. K. Year 2019 Mechanical Actuation Systems Introduction When high bandwidth, high position accuracy and long stroke are required simultaneously: dual-stage systems composed of a coarse (or primary) actuator and a fine actuator working together are used. Popular choices for coarse actuator are: DC motor Voice coil motor (VCM) Permanent magnet stepper motor Permanent magnet linear synchronous motor As fine actuators, most of the time piezoelectric actuator are used. /zettels/multivariable_control/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/multivariable_control/ Tags : <./biblio/references.bib> Backlinks Position control in lithographic equipment Implementation challenges for multivariable control: what you did not learn in school! Simultaneous, fault-tolerant vibration isolation and pointing control of flexure jointed hexapods Multivariable control systems: an engineering approach Multivariable feedback control: analysis and design /book/albertos04_multiv_contr_system/ Mon, 01 Jan 0001 00:00:00 +0000 /book/albertos04_multiv_contr_system/ Tags Multivariable Control Reference (Albertos & Antonio, 2004) Author(s) Albertos, P., & Antonio, S. Year 2004 Bibliography Albertos, P., & Antonio, S., Multivariable control systems: an engineering approach (2004), : Springer-Verlag. ↩ /book/skogestad07_multiv_feedb_contr/ Mon, 01 Jan 0001 00:00:00 +0000 /book/skogestad07_multiv_feedb_contr/ Tags Reference Books, Multivariable Control Reference (Skogestad & Postlethwaite, 2007) Author(s) Skogestad, S., & Postlethwaite, I. Year 2007 \( % H Infini \newcommand{\hinf}{\mathcal{H}_\infty} % H 2 \newcommand{\htwo}{\mathcal{H}_2} % Omega \newcommand{\w}{\omega} % H-Infinity Norm \newcommand{\hnorm}[1]{\left\|#1\right\|_{\infty}} % H-2 Norm \newcommand{\normtwo}[1]{\left\|#1\right\|_{2}} % Norm \newcommand{\norm}[1]{\left\|#1\right\|} % Absolute value \newcommand{\abs}[1]{\left\lvert#1\right\lvert} % Maximum for all omega \newcommand{\maxw}{\text{max}_{\omega}} % Maximum singular value \newcommand{\maxsv}{\overline{\sigma}} % Minimum singular value \newcommand{\minsv}{\underline{\sigma}} % Under bar \newcommand{\ubar}[1]{\text{\b{$#1$}}} % Diag keyword \newcommand{\diag}[1]{\text{diag}\{{#1}\}} % Vector \newcommand{\colvec}[1]{\begin{bmatrix}#1\end{bmatrix}} \) \( \newcommand{\tcmbox}[1]{\boxed{#1}} % Simulate SIunitx \newcommand{\SI}[2]{#1\,#2} \newcommand{\ang}[1]{#1^{\circ}} \newcommand{\degree}{^{\circ}} \newcommand{\radian}{\text{rad}} \newcommand{\percent}{\%} \newcommand{\decibel}{\text{dB}} \newcommand{\per}{/} % Bug with subequations \newcommand{\eatLabel}[2]{} \newenvironment{subequations}{\eatLabel}{} \) Introduction /zettels/nano_active_stabilization_system/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/nano_active_stabilization_system/ Tags : <./biblio/references.bib> Backlinks Interferometric characterization of rotation stages for x-ray nanotomography Automated markerless full field hard x-ray microscopic tomography at sub-50 nm 3-dimension spatial resolution An instrument for 3d x-ray nano-imaging /paper/furutani04_nanom_cuttin_machin_using_stewar/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/furutani04_nanom_cuttin_machin_using_stewar/ Tags Stewart Platforms, Flexible Joints Reference (Katsushi Furutani {\it et al.}, 2004) Author(s) Furutani, K., Suzuki, M., & Kudoh, R. Year 2004 Lever mechanism to amplify the motion of piezoelectric stack actuators Use of flexure joints Eddy current displacement sensors for control (decentralized) Isotropic performance (cubic configuration even if not said so) Possible sources of error: position error of the link ends in assembly => simulation of position error and it is not significant Inaccurate modelling of the links insufficient generative force unwanted deformation of the links To minimize the errors, a calibration is done between the required leg length and the wanted platform pose. /paper/fleming10_nanop_system_with_force_feedb/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/fleming10_nanop_system_with_force_feedb/ Tags Sensor Fusion, Force Sensors Reference (Fleming, 2010) Author(s) Fleming, A. Year 2010 Summary: The noise generated by a piezoelectric force sensor is much less than a capacitive sensor Dynamical model of a piezoelectric stack actuator and piezoelectric force sensor Noise of a piezoelectric force sensor IFF with a piezoelectric stack actuator and piezoelectric force sensor A force sensor is used as a displacement sensor below the frequency of the first zero Sensor fusion architecture with a capacitive sensor and a force sensor and using complementary filters Virtual sensor fusion architecture (called low-frequency bypass) Analog implementation of the control strategies to avoid quantization noise, finite resolution and sampling delay Model of a multi-layer monolithic piezoelectric stack actuator /paper/sebastian12_nanop_with_multip_sensor/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/sebastian12_nanop_with_multip_sensor/ Tags Sensor Fusion Reference (Abu Sebastian & Angeliki Pantazi, 2012) Author(s) Sebastian, A., & Pantazi, A. Year 2012 Bibliography Sebastian, A., & Pantazi, A., Nanopositioning with multiple sensors: a case study in data storage, IEEE Transactions on Control Systems Technology, 20(2), 382–394 (2012). http://dx.doi.org/10.1109/tcst.2011.2177982 ↩ /book/taghirad13_paral/ Mon, 01 Jan 0001 00:00:00 +0000 /book/taghirad13_paral/ Tags Stewart Platforms, Reference Books Reference (Taghirad, 2013) Author(s) Taghirad, H. Year 2013 Introduction This book is intended to give some analysis and design tools for the increase number of engineers and researchers who are interested in the design and implementation of parallel robots. A systematic approach is presented to analyze the kinematics, dynamics and control of parallel robots. To define the motion characteristics of such robots, it is necessary to represent 3D motion of the robot moving platform with respect to a fixed coordinate. /paper/butler11_posit_contr_lithog_equip/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/butler11_posit_contr_lithog_equip/ Tags Multivariable Control, Positioning Stations Reference (Hans Butler, 2011) Author(s) Butler, H. Year 2011 Bibliography Butler, H., Position control in lithographic equipment, IEEE Control Systems, 31(5), 28–47 (2011). http://dx.doi.org/10.1109/mcs.2011.941882 ↩ /zettels/position_sensors/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/position_sensors/ Tags Inertial Sensors Reviews of position sensors (Collette {\it et al.}, 2012) Fleming, A. J., A review of nanometer resolution position sensors: operation and performance (Andrew Fleming, 2013) (Notes) Relative Position Sensors Table 1: Characteristics of relative measurement sensors collette11_review Technology Frequency Resolution Range T Range LVDT DC-200 Hz 10 nm rms 1-10 mm -50,100 °C Eddy current 5 kHz 0. /zettels/positioning_stations/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/positioning_stations/ Tags : <./biblio/references.bib> Backlinks Interferometric characterization of rotation stages for x-ray nanotomography Position control in lithographic equipment An instrument for 3d x-ray nano-imaging /zettels/precision_engineering/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/precision_engineering/ Tags : <./biblio/references.bib> Backlinks Design for precision: current status and trends Basics of precision engineering - 1st edition /zettels/reference_books/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/reference_books/ Tags : <./biblio/references.bib> Backlinks Modal testing: theory, practice and application The art of electronics - third edition Vibration Control of Active Structures - Fourth Edition Parallel robots : mechanics and control The design of high performance mechatronics - 2nd revised edition Multivariable feedback control: analysis and design /paper/collette11_review_activ_vibrat_isolat_strat/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/collette11_review_activ_vibrat_isolat_strat/ Tags Vibration Isolation Reference (Christophe Collette {\it et al.}, 2011) Author(s) Collette, C., Janssens, S., & Artoos, K. Year 2011 Background and Motivations Passive Isolation Tradeoffs \[ X(s) = \underbrace{\frac{cs + k}{ms^2 + cs + k}}_{T_{wx}(s)} W(s) + \underbrace{\frac{1}{ms^2 + cs + k}}_{T_{Fx}(s)} F(s) \] \(T_{wx}(s)\) is called the transmissibility of the isolator. It characterize the way seismic vibrations \(w\) are transmitted to the equipment. \(T_{Fx}(s)\) is called the compliance. /search/ Mon, 01 Jan 0001 00:00:00 +0000 /search/ This file exists solely to respond to /search URL with the related search layout template. No content shown here is rendered, all content is based in the template layouts/page/search.html Setting a very low sitemap priority will tell search engines this is not important content. This implementation uses Fusejs, jquery and mark.js Initial setup Search depends on additional output content type of JSON in config.toml ``` [outputs] home = [“HTML”, “JSON”] ``` /zettels/sensor_fusion/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/sensor_fusion/ Tags : <./biblio/references.bib> Backlinks Sensor fusion for active vibration isolation in precision equipment Vibration control of flexible structures using fusion of inertial sensors and hyper-stable actuator-sensor pairs Sensor fusion methods for high performance active vibration isolation systems Nanopositioning system with force feedback for high-performance tracking and vibration control Nanopositioning with multiple sensors: a case study in data storage /paper/tjepkema12_sensor_fusion_activ_vibrat_isolat_precis_equip/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/tjepkema12_sensor_fusion_activ_vibrat_isolat_precis_equip/ Tags Sensor Fusion, Vibration Isolation Reference (Tjepkema {\it et al.}, 2012) Author(s) Tjepkema, D., Dijk, J. v., & Soemers, H. Year 2012 Relative motion Control Control law: \(f = -G(x-w)\) \[ \frac{x}{w} = \frac{k+G}{ms^2 + k+G} \] \[ \frac{x}{F} = \frac{1}{ms^2 + k+G} \] Force Control Control law: \(f = -G F_a = -G \left(f-k(x-w)\right)\) \[ \frac{x}{w} = \frac{k}{(1+G)ms^2 + k} \] \[ \frac{x}{F} = \frac{1+G}{(1+G)ms^2 + k} \] /paper/collette15_sensor_fusion_method_high_perfor/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/collette15_sensor_fusion_method_high_perfor/ Tags Sensor Fusion, Vibration Isolation Reference (Collette & Matichard, 2015) Author(s) Collette, C., & Matichard, F. Year 2015 In order to have good stability margins, it is common practice to collocate sensors and actuators. This ensures alternating poles and zeros along the imaginary axis. Then, each phase lag introduced by the poles is compensed by phase leag introduced by the zeroes. This guarantees stability and such system is referred to as hyperstable. /paper/hauge04_sensor_contr_space_based_six/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/hauge04_sensor_contr_space_based_six/ Tags Stewart Platforms, Vibration Isolation, Cubic Architecture Reference (Hauge & Campbell, 2004) Author(s) Hauge, G., & Campbell, M. Year 2004 Discusses: Choice of sensors and control architecture Predictability and limitations of the system dynamics Two-Sensor control architecture Vibration isolation using a Stewart platform Experimental comparison of Force sensor and Inertial Sensor and associated control architecture for vibration isolation Figure 1: Hexapod for active vibration isolation /paper/li01_simul_vibrat_isolat_point_contr/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/li01_simul_vibrat_isolat_point_contr/ Tags Stewart Platforms, Vibration Isolation Reference (Xiaochun Li {\it et al.}, 2001) Author(s) Li, X., Hamann, J. C., & McInroy, J. E. Year 2001 if the hexapod is designed such that the payload mass/inertia matrix (\(M_x\)) and \(J^T J\) are diagonal, the dynamics from \(u\) to \(y\) are decoupled. Bibliography Li, X., Hamann, J. C., & McInroy, J. E., Simultaneous vibration isolation and pointing control of flexure jointed hexapods, In , Smart Structures and Materials 2001: Smart Structures and Integrated Systems (pp. /paper/li01_simul_fault_vibrat_isolat_point/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/li01_simul_fault_vibrat_isolat_point/ Tags Stewart Platforms, Vibration Isolation, Cubic Architecture, Flexible Joints, Multivariable Control Reference @phdthesis{li01_simul_fault_vibrat_isolat_point, author = {Li, Xiaochun}, school = {University of Wyoming}, title = {Simultaneous, Fault-tolerant Vibration Isolation and Pointing Control of Flexure Jointed Hexapods}, year = 2001, tags = {parallel robot}, } Author(s) Li, X. Year 2001 Introduction Stewart Platform: Cubic (mutually orthogonal) Flexure Joints => eliminate friction and backlash but add complexity to the dynamics /paper/zhang11_six_dof/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/zhang11_six_dof/ Tags Stewart Platforms, Vibration Isolation Reference (Zhen Zhang {\it et al.}, 2011) Author(s) Zhang, Z., Liu, J., Mao, J., Guo, Y., & Ma, Y. Year 2011 Non-cubic stewart platform Flexible joints Magnetostrictive actuators Strong coupled motions along different axes Non-cubic architecture => permits to have larger workspace which was required Structure parameters (radius of plates, length of struts) are determined by optimization of the condition number of the Jacobian matrix Accelerometers for active isolation Adaptive FIR filters for active isolation control /zettels/stewart_platforms/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/stewart_platforms/ Tags : <./biblio/references.bib> Backlinks Six dof active vibration control using stewart platform with non-cubic configuration Decentralized vibration control of a voice coil motor-based stewart parallel mechanism: simulation and experiments Dynamic modeling and decoupled control of a flexible stewart platform for vibration isolation Parallel robots : mechanics and control Investigation on active vibration isolation of a stewart platform with piezoelectric actuators Identification and decoupling control of flexure jointed hexapods The stewart platform manipulator: a review Modeling and control of vibration in mechanical systems Studies on stewart platform manipulator: a review Nanometre-cutting machine using a stewart-platform parallel mechanism An intelligent control system for multiple degree-of-freedom vibration isolation Active isolation and damping of vibrations via stewart platform Sensors and control of a space-based six-axis vibration isolation system Dynamic modeling and experimental analyses of stewart platform with flexible hinges Simultaneous, fault-tolerant vibration isolation and pointing control of flexure jointed hexapods A new isotropic and decoupled 6-dof parallel manipulator Simultaneous vibration isolation and pointing control of flexure jointed hexapods A six-axis single-stage active vibration isolator based on stewart platform Vibration Control of Active Structures - Fourth Edition A soft 6-axis active vibration isolator /paper/furqan17_studies_stewar_platf_manip/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/furqan17_studies_stewar_platf_manip/ Tags Stewart Platforms Reference (Mohd Furqan {\it et al.}, 2017) Author(s) Furqan, M., Suhaib, M., & Ahmad, N. Year 2017 Lots of references. Bibliography Furqan, M., Suhaib, M., & Ahmad, N., Studies on stewart platform manipulator: a review, Journal of Mechanical Science and Technology, 31(9), 4459–4470 (2017). http://dx.doi.org/10.1007/s12206-017-0846-1 ↩ /zettels/system_identification/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/system_identification/ Tags : <./biblio/references.bib> Backlinks Modal testing: theory, practice and application /zettels/test/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/test/ This is a quote! 1 2 a = 2; figure; This is an important part of the text. See Eq. eq:test1 and eq:test2. \begin{equation} a = 1 \end{equation} \begin{equation} a = 2 \label{eq:test2} \end{equation} Also look at 1 \eqref{eq:test2}. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. Some text. /book/horowitz15_art_of_elect_third_edition/ Mon, 01 Jan 0001 00:00:00 +0000 /book/horowitz15_art_of_elect_third_edition/ Tags Reference Books, Electronics Reference (Horowitz, 2015) Author(s) Horowitz, P. Year 2015 Bibliography Horowitz, P., The art of electronics - third edition (2015), New York, NY, USA: Cambridge University Press. ↩ /book/schmidt14_desig_high_perfor_mechat_revis_edition/ Mon, 01 Jan 0001 00:00:00 +0000 /book/schmidt14_desig_high_perfor_mechat_revis_edition/ Tags Reference Books Reference (Schmidt {\it et al.}, 2014) Author(s) Schmidt, R. M., Schitter, G., & Rankers, A. Year 2014 Section 2.2 Mechanics The core of a mechatronic system is its mechanical construction and in spite of many decade of excellent designs, optimizing the mechanical structure in strength, mass and endurance, the mechanical behavior will always remain the limiting factor of the performance of any mechatronic system. /paper/dasgupta00_stewar_platf_manip/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/dasgupta00_stewar_platf_manip/ Tags Stewart Platforms Reference (Bhaskar Dasgupta & Mruthyunjaya, 2000) Author(s) Dasgupta, B., & Mruthyunjaya, T. Year 2000 Table 1: Parallel VS serial manipulators Advantages Disadvantages Serial Manoeuverability Poor precision Large workspace Bends under high load Vibrate at high speed Parallel High stiffness Small workspace Good dynamic performances Precise positioning The generalized Stewart platforms consists of two rigid bodies (referred to as the base and the platoform) connected through six extensible legs, each with sherical joints at both ends. /book/preumont18_vibrat_contr_activ_struc_fourt_edition/ Mon, 01 Jan 0001 00:00:00 +0000 /book/preumont18_vibrat_contr_activ_struc_fourt_edition/ Tags Vibration Isolation, Reference Books, Stewart Platforms, HAC-HAC Reference (Andre Preumont, 2018) Author(s) Preumont, A. Year 2018 Introduction Active Versus Passive Active structure may be cheaper or lighter than passive structures of comparable performances; or they may offer performances that no passive structure could offer. Active is not always better, and a control systems cannot compensate for a bad design. Active solution should be considered only after all other passive means have been exhausted. /paper/collette14_vibrat/ Mon, 01 Jan 0001 00:00:00 +0000 /paper/collette14_vibrat/ Tags Vibration Isolation, Sensor Fusion Reference (Collette & Matichard, 2014) Author(s) Collette, C., & Matichard, F. Year 2014 Introduction Sensor fusion is used to combine the benefits of different types of sensors: Relative sensor for DC positioning capability at low frequency Inertial sensors for isolation at high frequency Force sensor / collocated sensor to improve the robustness Different types of sensors In this paper, three types of sensors are used. /zettels/vibration_isolation/ Mon, 01 Jan 0001 00:00:00 +0000 /zettels/vibration_isolation/ Tags : <./biblio/references.bib> Backlinks Six dof active vibration control using stewart platform with non-cubic configuration Dynamic modeling and decoupled control of a flexible stewart platform for vibration isolation Investigation on active vibration isolation of a stewart platform with piezoelectric actuators Review of active vibration isolation strategies Vibration control of flexible structures using fusion of inertial sensors and hyper-stable actuator-sensor pairs Sensor fusion methods for high performance active vibration isolation systems Modeling and control of vibration in mechanical systems An intelligent control system for multiple degree-of-freedom vibration isolation Active isolation and damping of vibrations via stewart platform Sensors and control of a space-based six-axis vibration isolation system Comparison and classification of high-precision actuators based on stiffness influencing vibration isolation Simultaneous, fault-tolerant vibration isolation and pointing control of flexure jointed hexapods Simultaneous vibration isolation and pointing control of flexure jointed hexapods An exploration of active hard mount vibration isolation for precision equipment Force feedback versus acceleration feedback in active vibration isolation A six-axis single-stage active vibration isolator based on stewart platform Vibration Control of Active Structures - Fourth Edition A soft 6-axis active vibration isolator Sensor fusion for active vibration isolation in precision equipment