Independent All-Wheel Drive Technology for Electric Vehicles

1. Introduction

1.1 Introduction to All-wheel-drive Electric Vehicles

1.2 Key Technologies for All-wheel-drive Electric Vehicle Drive

1.2.1 Vehicle driving state estimation technology

1.2.2 Wheel motor technology

1.2.3 Electronic differential control

1.2.4 Stability Control

1.2.5 Drive anti-skid control

1.2.6 Energy saving control

1.3 Current Problems


2. Fundamentals and Basic Performance of Automotive Dynamics

2.1 Dynamics of automobiles

2.1.1 Vehicle Dynamics

2.2 Driving principle of automobiles

2.2.1 Force analysis during vehicle operation

2.2.2 Wheel Slip and Adhesion Characteristics

2.3 Steering performance of distributed drive electric vehicles

2.3.1 Ackermann steering geometry relationship during two wheel steering

2.3.2 Ackermann steering geometry relationship during four-wheel steering

2.3 Actual Ackermann turning geometry relationship

2.4 Vehicle handling stability performance

2.4.1 Slip theory under combined longitudinal and lateral slip conditions of tires

2.4.2 Tire slip ratio and wheel center speed

2.4.3 Driver Model

2.4.4 Lateral angular velocity and center of mass lateral deviation angle

2.5 Braking Performance of Distributed Drive Electric Vehicles

2.5.1 Automotive Braking Process

2.5.2 Evaluation indicators for automobile braking performance

2.5.3 Distribution of four-wheel braking force for distributed drive electric vehicles


3. Drive System Structure of All-wheel-drive Electric Vehicles

3.1 Overview of All-wheel-drive System Structure

3.1.1 Concentrated opposed wheel edge motor structure

3.1.2 Wheel motor structure

3.2 Motor Structure Principle

3.2.1 DC motor

3.2.2 AC three-phase induction motor

3.2.3 Permanent magnet motor

3.3 Planetary gear transmission characteristics

3.4 Structure of Centralized Drive Axle

3.5 Distributed Drive Vehicle Control Structure


4. Parameter Matching of All-wheel-drive Electric Vehicles

4.1 Parameter matching of pure electric vehicles

4.1.1 Power performance of pure electric vehicles

4.1.2 Motor speed and torque

4.1.3 Matching of transmission ratio parameters

4.1.4 Matching of power battery

4.2 Motor selection and matching

4.2.1 Determination of motor power

4.2.2 Motor speed setting

4.2.3 Determination of motor torque

4.3 Dynamic matching of driving power for All-wheel-drive electric vehicles

4.3.1 The necessity of dynamic matching of driving power

4.3.2 Method for dynamic matching of driving power

4.3.3 Torque Control Allocation Model Based on Optimal Efficiency

4.3.4 Principle of torque control allocation based on optimal efficiency


5. Estimation of Vehicle Driving Status

5.1 Vehicle driving state estimation based on Kalman filter

5.1.1 Kalman Filter Theory

5.1.2 Basic Equation of Kalman Filter for Discrete Systems

5.1.3 Basic Equation of Kalman Filter for Continuous Systems

5.2 Implementation of Kalman Filter in MATLAB

5.3 Relationship between driving force, slip rate, parasitic power and driving motor current

5.3.1 Relationship between driving force, slip rate and driving motor current of the driving wheel

5.3.2 Relationship between Parasitic Power and Drive Motor Current

5.4 Estimation method for the lateral deviation angle of the vehicle's center of mass

5.4.1 Dynamic equations of vehicle model

5.4.2 System composition of hybrid observer

5.4.3 Dynamics Integral Estimation Module

5.4.4 Vehicle stability discrimination

5.4.5 Weight Calculation of Fuzzy Controller

5.4.6 Hybrid Observer


6. Drive Torque Control for Handling Stability of All-wheel-drive Electric Vehicles

6.1 Analysis of Target Parameters for Vehicle Stability Control

6.1.1 Vehicle stability characterization parameters

6.1.2 Establishment of Nonlinear Vehicle Reference Model

6.1.3 Determination of Constrained Target Yaw Angular Velocity

6.2 Design of yaw moment controller based on improved sliding mode control algorithm

6.2.1 Analysis of Sliding Mode Control Theory

6.2.2 Design of Lateral Torque Controller

6.2.3 Improvement of yaw moment controller based on RBF neural network

6.3 Design of Drive Torque Distribution Control Strategy

6.4 Simulation analysis of stability torque control under steering conditions

6.4.1 Simulation Platform

6.4.2 Simulation Experiment Design and Analysis


7. Electronic Differential Control of All-wheel-drive Electric Vehicles

7.1 Analysis of Electronic Differential Scheme

7.1.1 The Importance of Differential Speed

7.1.2 Principle of mechanical differential

7.1.3 Electronic differential scheme

7.2 Electronic Differential Control Strategy

7.2.1 Overall design concept

7.2.2 Vehicle speed estimation

7.2.3 Load based allocation principle

7.2.4 Slip Correction Based on Speed Constraints

7.2.5 Torque Distribution Module

7.3 Modeling of Differential Algorithm

7.4 Design of Electronic Differential

7.4.1 Hardware Design of Electronic Differential Controller

7.4.2 Software Design of Electronic Differential Controller

7.4.3 System Software Architecture

7.4.4 Control Process

7.4.5 Bottom level development and model code generation

7.5 Electronic Differential Simulation Analysis

7.5.1 50km/h double track operating condition

7.5.2 120km/h double track operating condition


8. Vehicle Drive Anti Slip Control Based on Wheel Slip State Estimation

8.1 Distributed Drive Electric Vehicle Drive Anti Slip Control Scheme

8.2 Model Tracking Control (MFC) 8.3 Principle of judging wheel slip state

8.3.1 Principle of wheel slip state judgment based on wheel angular acceleration value

8.3.2 Determination of wheel slip state

8.4 Fuzzy control algorithm based on wheel slip state and wheel angular acceleration

8.4.1 Selection of threshold values for wheel angular acceleration control

8.4.2 Parameter based Wheel Slip State Observer

8.4.3 Design of Drive Anti Slip Fuzzy Controller Based on Parameters and Wheel Angular Acceleration

8.5 Simulation experiment of driving anti-skid control system based on longitudinal driving safety of electric wheel vehicles

8.5.1 Simulation analysis of low adhesion pavement

8.5.2 Simulation analysis of medium high adhesion pavement

8.5.3 Docking Road Simulation Analysis

8.6 Simulation experiment on robustness of fuzzy control algorithm with dual parameter input

8.6.1 Simulation results of vehicles with different quality parameters on low attachment road surfaces

8.6.2 Simulation results of vehicles with different quality parameters under docking road conditions


9. Energy saving Drive Torque Control Strategy for All-wheel-drive Electric Vehicles

9.1 Energy consumption analysis of wheel hub motor electric vehicle system

9.2 Wheel motor bench test

9.2.1 Working principle of wheel hub motor test bench

9.2.2 Experimental Design of Wheel Motor Characteristics

9.3 Research on torque energy-saving optimization allocation algorithm

9.3.1 Optimization Goal Selection

9.3.2 Determination of Constraints

9.3.3 Solving energy-saving optimization allocation algorithm

9.4 Simulation analysis of energy-saving torque control under straight-line working conditions

9.4.1 Introduction to chassis dynamometer test bench experiment based on D2P rapid prototyping

9.4.2 Analysis of Experimental Results


10. All-wheel-drive Electric Vehicle Drive Fault Compensation Control

10.1 Fault analysis of All-wheel-drive electric vehicle actuators

10.1.1 Single motor failure

10.1.2 Dual motor malfunction

10.2 Motor Fault Model

10.3 Design of actuator fault compensation

10.3.1 Backstepping Control Design

10.3.2 Adaptive Fault Compensation Design

10.3.3 Performance Analysis


11. Thermal Analysis of Electric Vehicle Wheel Hub Motor

11.1 Thermal loss analysis of electric vehicle wheel hub motor

11.2 Temperature field of wheel hub motor

11.2.1 Heat transfer analysis of temperature field in wheel hub motor

11.2.2 Temperature field analysis of wheel hub motor

11.3 Cooling analysis of permanent magnet wheel hub motor

11.4 Analysis of liquid cooling structure for wheel hub motor

11.4.1 Hub Motor Liquid Cooling Pipeline Structure

11.4.2 Analysis of inlet and outlet pressure difference of liquid cooling structure

11.4.3 Determination of coolant flow rate in cooling pipelines

11.4.4 Flow field model of cooling system