Development and Series Application of a Vehicle Drivetrain Observer Used in Hybrid and Electric Vehicles

Abstract

This paper introduces the development and calibration process of a vehicle drivetrain observer used in hybrid and electric vehicles for active damping control (ADC) and for the improvement of the electric machine's rotor angle signal quality. This approach starts with creating an overall vehicle model that includes the electric machine, the transmission, side shafts, the tires and the vehicle body. For control engineering purposes, that multi-order-model is then reduced into a two-mass-oscillator which can be easily described in state-space form. Using this reduced drivetrain model and applying a Luenberger observer approach, not only the signal quality of both the instrumented rotor angle and the speed of the electric machine can be improved considerably but also the oscillation dynamics of this vehicle drivetrain can be estimated. If not compensated during vehicle operation, drivetrain oscillations might lead to increased drivetrain wear, NVH issues and limited ride comfort; therefore, the oscillation speed is very important in computing an active damping torque that is to compensate drivetrain oscillations. Calibration of the vehicle drivetrain observer is done using specific vehicle test data that are fed into a standalone calibration tool identifying the parameters of the vehicle drivetrain as well as the Luenberger feedback vector. Based on these data, a proper active damping control application is set-up and verified in various vehicle tests and to lead to the calibration finally to the application in several hybrid and electric vehicle series projects (e.g. Peugeot 3008 HYbrid4).

Performans ve sürülebilirlik ölçütlerini sağlamak için motor kontrol ünitesinin çevrimiçi optimizasyonu

“…Sarsıntı önleyici kontrol, sönümlü salınımlar olarak da adlandırılan uzunlamasına araç salınımlarını azaltır. Bu salınımlar araç konforunu, sürülebilirliğini ve aktarma organları bileşeninin dayanıklılığını da etkilemektedir [13,14].…”

Detection of Torque Security Problems Based on the Torsion of Side Shafts in Electrified Vehicles

“…For a long time, vehicle drivetrain observers have been used in hybrid and electric vehicles to improve the active damping control [16][17][18]. According to [19], these represent a method of optimizing active damping control in the low velocity range, particularly with regard to jerking at driving-off.…”

“…Another typical approach for an observer with the model of a drivetrain is described in [18]. The used Luenberger observer is based on a simplified mechanical model of the drivetrain.…”

“…However, the consideration of the air gap torque of the drive machine, e.g., based on the explanations in [20], may be critical with regard to functional safety. As described in [18,20], the air gap torque of the drive machine can be estimated using external control units or by a model. In the event of a fault, this estimate can deviate from reality and therefore result in an incorrect estimate of the side shaft torque.…”

Performance Prediction of a 4WD High-Performance Electric Vehicle Using a Model-Based Torque-Vectoring Approach

“…The advantage of using the four individual motors configuration is that it allows for precise torque distribution when applying the maximum motor power [7][8][9][10][11]. This solution allows individual control of the driving torque at each wheel and thus quickly deploys Torque Vectoring Control (TVC) to stabilize the vehicle and increase its performance [12][13][14][15]. Torque-vectoring control systems are designed to optimize the distribution of torque to individual wheels or axles, enhancing vehicle stability, agility, and overall performance.…”