Co-Simulation of BLDC Motor Control and Clutch actuation system with Ball Ramp Mechanism

Electro-mechanical actuators are widely used in different forms in the automotive industry these days and are very effective in translating rotary motion of the motor to a linear motion with precision as per the requirement. With onset of electric drivelines and other complex driveline configurations, we see an increase in actuator applications. In this study, we developed high fidelity analytical model for a ball ramp clutch actuation system as per the proposed mechanical design and the software controls. The controls architecture is built in SIMULINK environment to drive the plant model of the BLDC motor. Whereas, the entire mechanical system which includes the gear train, ball ramp mechanism, clutch pack stiffness, etc. is modelled in ADAMS tool. The Ball Ramp consists of metal balls positioned in between opposing paired arc-shaped ramp grooves and guided by a cage to keep them equally separated in the same plane. While ADAMS model deals with high-fidelity contact dynamics using non-linear solid to solid contact joints, the SIMULINK model implements the Field oriented control (FOC) algorithm for closed loop position control of the motor shaft. The position request to the controller is dependent on clutch torque requirement. In this application, a three-stage nested loop is used to control the position, velocity and the current/torque. The speed controller provides the necessary Id, Iq reference values required for the field-oriented control. Finally, the motor output from the Simulink model is taken as the load boundary condition in ADAMS model using co-simulation. The combination of controls model and the mechanical system model ensures proper boundary conditions, mimicking the real conditions. The goal of this work is to study system response to different command torque requests and to assess feasibility of actuation response time target by monitoring different metrics.