Electrification of forestry cranes : from hydraulics to sustainable motion
Saad, Muhammad (2025)
Diplomityö
2025
School of Energy Systems, Konetekniikka
Kaikki oikeudet pidätetään.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe20251216120117
https://urn.fi/URN:NBN:fi-fe20251216120117
Tiivistelmä
This thesis examines the replacement of hydraulic cylinders with electromechanical actuators (EMAs) in a multi-degree-of-freedom construction crane and evaluates the consequences for dynamic performance and actuation behavior. A high-fidelity constrained multibody system (MBS) model is developed, incorporating rigid-body kinematics, holonomic constraints, and accurate actuator–joint geometry. The lift and tilt joints are driven through screw-type EMAs powered by a permanent-magnet synchronous motor (PMSM). A complete d–q axis PMSM representation, capturing stator flux linkages, current dynamics, and electromagnetic torque production, is integrated with a field-oriented control (FOC) scheme to reflect realistic electromechanical coupling.
Coordinated lift–tilt motion sequences are simulated to assess joint trajectories, actuator forces, torque generation, and mechanical power flow across defined motion phases. The results indicate distinct dynamic characteristics compared to hydraulic actuation, driven primarily by reflected inertia, electrical time constants, and transmission stiffness. To quantify parameter influence, a systematic sensitivity analysis is conducted on transmission ratio, rotor inertia, stator resistance, and permanent-magnet flux linkage. Their impact on motion-tracking accuracy, peak mechanical power, and energy distribution during the motion cycle is identified and documented.
The findings contribute to understanding the feasibility and performance implications of implementing EMA-based actuation in heavy-duty crane applications and provide guidance for motor–transmission selection and electromechanical parameterization.
Coordinated lift–tilt motion sequences are simulated to assess joint trajectories, actuator forces, torque generation, and mechanical power flow across defined motion phases. The results indicate distinct dynamic characteristics compared to hydraulic actuation, driven primarily by reflected inertia, electrical time constants, and transmission stiffness. To quantify parameter influence, a systematic sensitivity analysis is conducted on transmission ratio, rotor inertia, stator resistance, and permanent-magnet flux linkage. Their impact on motion-tracking accuracy, peak mechanical power, and energy distribution during the motion cycle is identified and documented.
The findings contribute to understanding the feasibility and performance implications of implementing EMA-based actuation in heavy-duty crane applications and provide guidance for motor–transmission selection and electromechanical parameterization.