Mode-switch model predictive controller with “pre-contact” method for alleviating driveline vibration of electric vehicles considering backlash

Abstract

The backlash between engaging components in a driveline is inevitable and contributes to the nonlinearity of the driveline. The existing motor controllers of an electric vehicle usually ignore the backlash, which often brings impacts and vibration. This paper proposes an active driveline vibration controller for electric vehicles. A nonlinear driveline model considering backlash and wheel slip ratio is established in MATLAB/Simulink, and the results of bench test proved that the model could effectively reflect the transient dynamics of the electric driveline. Based on this model, a dual extended Kalman filter observer is designed to estimate both the system state variables and vehicle mass, which are essential information for the controller design. Then, a mode-switch model predictive controller based on two linearized models is proposed to alleviate the impacts and vibration caused by the transient change of motor torque. The proposed controller would identify whether the driveline is operating in “contact mode” or “backlash mode” and thus generates an optimal motor torque by solving a Quadratic Programing. Note that the control targets and model structures in two modes are different. Furthermore, a “pre-contact” method is proposed as an additional part to handle the condition when motor command torque is zero. Simulation results demonstrate that the proposed controller can effectively alleviate the impacts and vibration in the electric driveline while keeping the torque delay negligible. Moreover, the robustness of the proposed controller against estimation errors and system noises are discussed.

Active vibration control of automobile drivetrain with backlash considering time-varying long control period

“…In this study, the cut-off frequency was determined as 10–30 Hz with a sufficient margin from the first natural frequency of 4.0 Hz. The gain in the passband of the low-pass filter becomes a weighting constant in minimizing the H 2 norm 25–27 of z 1 when designing the controller in Figure 4(a). Therefore, designing its value to be too small may lead to an insufficient transient vibration performance.…”

“…8 In particular, many outcomes are related to model predictive control (MPC). 9–14 These are broadly considered to be effective techniques. A mode-switching-based active control algorithm including the sliding mode technique and PID control has been investigated by simulation studies.…”

Novel Powertrain Vibration Controller With Six Rules-Based Fuzzy Inference for Time-Fluctuated Control Period

“…Many control strategies have been investigated, including sliding mode control [7], [8], switching control of linear-quadratic regulator (LQR) [9], and model reference adaptive Linear Quadratic Tracking (ALQT) control [10]. Additionally, model predictive control (MPC) is widely used in many attempts [11]- [14]. The complicated properties of powertrain systems, such as nonlinearities and mechanical constraints, are however accommodated by standard MPC through computationally intensive optimization calculations and elaborate modeling.…”

Experimental verification of active oscillation controller for vehicle drivetrain with backlash nonlinearity based on norm-limited SPSA

“…27 To address undesired oscillations due to backlash, the online MPC, which is a quadratic form-defined optimal control in a receding horizon, has been implemented. 28 In the literatures, 29,30 switching strategies for multiple predictive controllers have addressed the nonlinearity in a powertrain. The MPC controller can produce ideal responses including little error states such as excessive jerks and transient oscillations.…”