TY - GEN
T1 - Efficient formulation of hexapod kinematics enabling real time adaptive feedforward control
AU - Seinhorst, Bram
AU - Hakvoort, Wouter
N1 - Publisher Copyright:
© 2021 IEEE.
PY - 2021/8/24
Y1 - 2021/8/24
N2 - The tracking performance of manipulators can be improved considerably by adaptive feedforward control (AFFC). However, complex kinematics hinder the application to parallel kinematic manipulators (PKMs). This paper proposes a compact and efficient formulation of the full PKM kinematics enabling real-time application of AFFC to complex PKMs. The efficient kinematic formulation is the basis for the inverse dynamics used to compute the feedforward signal. A Kalman filter is used for online estimation of the parameters in the equations of motion. A parallel multi-rate implementation is used, which, together with the efficient kinematic formulation, allows for a feedforward sampling time as low as 0.5 ms. The parameters are updated every 30ms, which suffices to track the slow parameter variations. The application to a highly repeatable flexure-based manipulator is considered. Experimental results for the manipulator show that the tracking error can be reduced by 97.5% compared to using feedback control only.
AB - The tracking performance of manipulators can be improved considerably by adaptive feedforward control (AFFC). However, complex kinematics hinder the application to parallel kinematic manipulators (PKMs). This paper proposes a compact and efficient formulation of the full PKM kinematics enabling real-time application of AFFC to complex PKMs. The efficient kinematic formulation is the basis for the inverse dynamics used to compute the feedforward signal. A Kalman filter is used for online estimation of the parameters in the equations of motion. A parallel multi-rate implementation is used, which, together with the efficient kinematic formulation, allows for a feedforward sampling time as low as 0.5 ms. The parameters are updated every 30ms, which suffices to track the slow parameter variations. The application to a highly repeatable flexure-based manipulator is considered. Experimental results for the manipulator show that the tracking error can be reduced by 97.5% compared to using feedback control only.
UR - http://www.scopus.com/inward/record.url?scp=85114960915&partnerID=8YFLogxK
U2 - 10.1109/AIM46487.2021.9517402
DO - 10.1109/AIM46487.2021.9517402
M3 - Conference contribution
AN - SCOPUS:85114960915
SN - 978-1-6654-4140-7
T3 - IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM)
SP - 186
EP - 191
BT - 2021 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM 2021
PB - IEEE
CY - Piscataway, NJ
T2 - 2021 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM 2021
Y2 - 12 July 2021 through 16 July 2021
ER -