Distributed IMU, encoder and laser tracker data of a hydraulic flexible link

This dataset contains one experimental run of a hydraulic single-link flexible manipulator instrumented with inertial measurement units (IMUs) along the link. It accompanies the paper “Modular Geometric Complementary Filtering of Distributed IMUs and Deformation Observation for a Flexible Link” (S. Yaqubi, A. H. Barjini, J. Mattila). Experiment. The link is a 4.5 m steel beam with a 60 × 60 × 3 mm hollow section and a 20 kg payload at the end point. It is actuated by a hydraulic cylinder and moves in a vertical plane. Five Murata SCHA63T-K03 IMUs are mounted at 0.68, 1.53, 2.55, 3.51 and 4.44 m from the joint. A Leica AT960-LR laser tracker with a Leica T-Probe measures the position and orientation of the end point, and a SICK AFM60A absolute encoder (18-bit single-turn) measures the joint angle. All signals were read over EtherCAT by a Speedgoat real-time target machine. The run lasts 471 s, with 320,435 samples at irregular intervals (1 ms median). Content: signals.csv: the signals of the run as recorded. This covers the accelerometers and gyroscopes of the five IMUs, the encoder, the tracker position and pitch, and the end point of the coordinate IMU chain as logged by its real-time implementation. fig3_endpoint.csv and fig3b_tip_deflection.csv: the data of Fig. 3 of the paper, which are the end point position, pitch and velocity of the tracker and the estimates, and the in-plane tip deflection. fig4a_field.csv, fig4a_mode_shape.csv, fig4b_bending.csv, fig4c_joint_angle.csv and fig4d_imu5_pitch_error.csv: the data of Fig. 4. These are the modal coordinates and mode shapes of the deformation field, the bending angles at the stations of each IMU layout, the joint angle of the encoder, the observer and the accelerometers alone, and the IMU-5 pitch error of the reconstruction and of the observer. text_deflection_spectrum.csv, text_observer.csv and text_second_layout_endpoint.csv: values quoted in the paper but not plotted. These are the deflection spectrum at the first bending mode, the observer innovations, gains, bias estimates and conditioning, and the end point of the second IMU layout. parameters.json: the setup, processing settings, identified calibration constants and alignment constants. README.md: column definitions, frames and conventions, and check values computed from the exported columns that match the values reported in the paper. Fig. 5 of the paper is a simulation and is not part of this dataset.