VIT University, Chennai Performance Enhancement of Electronic Differential in Electric Vehicles Using a Novel Wavelet Controller Anish Bahri, Aditya Gupta, Febin Daya J L VIT University, Chennai Presented by: Aditya Gupta IEEE - ICVES 2014

OUTLINE OF THE TALK Introduction Brushless DC Drive IEEE - ICVES 2014 OUTLINE OF THE TALK Introduction Brushless DC Drive Electronic Differential Wavelet Controller Results and Discussions Conclusion References

INTRODUCTION IEEE - ICVES 2014 1. Differential: prevents vehicle from slipping on curved roads. 2. Electronic differential: Advanced Differential for: *better stability *better control on curved roads.

IEEE - ICVES 2014 3. Electronic differential- Control of PID controlled BLDC Drives 4. In this work- Replacement of PID with Wavelet controller. Comparison of simulation results through MATLAB/Simulink.

Fig. Block Diagram of BLDC Drive IEEE - ICVES 2014 BRUSHLESS DC DRIVE Fig. Block Diagram of BLDC Drive

ELECTRONIC DIFFERENTIAL IEEE - ICVES 2014 ELECTRONIC DIFFERENTIAL

Inputs to Electronic Differential - Angular velocity of vehicle IEEE - ICVES 2014 Inputs to Electronic Differential - Angular velocity of vehicle - Steering angle Outputs of Electronic Differential - Angular velocity of right wheel - Angular velocity of left wheel

ELECTRONIC DIFFERENTIAL MODELLING IEEE - ICVES 2014 ELECTRONIC DIFFERENTIAL MODELLING

IEEE - ICVES 2014 WAVELET CONTROLLER Discrete Wavelet Transform (DWT) : -> Time scale representation of a digital signal.

IEEE - ICVES 2014 WAVELET SELECTION * Simulations were carried out with different wavelets like Haar, Daubechies etc. * The Daubechies wavelet gave the best results. * The Minimum Description Length criterion is used for selection of wavelets.

WAVELET CONTROLLER Error signal: 1. Decomposed to- IEEE - ICVES 2014 WAVELET CONTROLLER Error signal: 1. Decomposed to- -Detailed coefficients (high frequency) -Approximation coefficients (low frequency) 2. Scaled by respective gain values 3. Added to generate control signal (u) kd1,kd2.. – gains for tuning high and medium frequency components Ka - gain for tuning low frequency components

SCHEMATIC OF WAVELET CONTROL IEEE - ICVES 2014 SCHEMATIC OF WAVELET CONTROL

RESULTS AND DISCUSSIONS IEEE - ICVES 2014 RESULTS AND DISCUSSIONS Case: Straight road followed by curved road Time Vector (s) : [0 0.2 0.3] Speed Input (km/hr): [60 60 60] Steering Angle Input (deg): [0° 30° 30°]

IEEE - ICVES 2014 Using PID Controller: Fig. Results of Left and Right Wheel Speed using PID Controller

Using Wavelet Controller: IEEE - ICVES 2014 Using Wavelet Controller: Fig. Results of Left and Right Wheel Speed using Wavelet Controller IEEE - ICVES 2014

IEEE - ICVES 2014 RESULT COMPARISON

Peak overshoot reduction- 0.69% Settling Time reduction- 6.12% IEEE - ICVES 2014 Peak overshoot reduction- 0.69% Settling Time reduction- 6.12%

IEEE - ICVES 2014 CONCLUSION -Results with Electronic differential and wavelet controlled BLDC Drives have improved. -Better stability -Better control during turns -Simulations showed that the wavelet controller performed better in both static and dynamic states thus ensuring high accuracy in the drive wheel speeds.

REFERENCES IEEE - ICVES 2014 [1] Ricardo Pinto de Castro, Hugo Santos Oliveira, Jos Ricardo Soares, Nuno Miguel Cerqueira and R. E. Araujo, A new FPGA based control system for electrical propulsion with electronic Differential. [2] Guillermo A. Magallan, Cristian H. De Angelo, Guillermo Bisheimer and Guillermo Garcia, A Neighborhood Electric Vehicle with Electronic Differential Traction Control. [3] Y. E. Zhao, J. W. Zhang and X. Q. Guan. Modeling and Simulation of Electronic Differential System for an Electric Vehicle with Two-Motor-Wheel Drive. [4] Azeddine Draou, Electronic Differential Speed Control for Two in wheels Motors Drive Vehicle in 4th International Conference on Power Engineering, Energy and Electrical Drives Istanbul, Turkey, 13-17 May 2013. [5] G. Stang and T. Nguyen, Wavelets and Wavelet Filter Banks. Wellesley, MA: Wellesley-Cambridge Press, 1996. [6] E. Y. Hamid and Z. I. Kawasaki, Wavelet based data compression of power system disturbances using the minimum description length criterion, IEEE Trans. Power Del., vol. 17, no. 2, pp. 460466, Apr. 2002.

THANK YOU IEEE - ICVES 2014