Research Of Micro EV Driven By In-wheel Motors Based On HTU Controller System

With the substantial growth of the global vehicle population, environmental pollution and energy shortages have become common concern of the society, thus the development of new Green Traffic has been more and more important. As a novel, efficient, energy saving, environmental protection, safety electric vehicles, EV driven by in-wheel motors which depends on its excellent performance and broad market prospects, will become the future direction of development of new energy vehicles.The dissertation provides an overview of the EV driven by in-wheel motor home and abroad, describes the motor control, electronic differential control, braking energy recovery mainly. A solution about four wheel-drives EV is given, and a micro-experimental EV driven by in-wheel motor has been manufactured for researching and developing EV.In this dissertation, the micro EV driven by four wheels adopts a master-slave network control structure, including a central controller and four motor-driven sub-modules. The HTU platform controller is selected as the central controller, mainly completes differential control through collecting gear position signal, steering angle signal, throttle position signal, brake signal from vehicles and speed, voltage, current and temperature signals from motor-driven sub-modules received by its one CAN communication interface. Besides it can communicate with the host computer HT_LINK via the other CAN communication interface and completes calibrating and monitoring vehicle control parameters in real time. PIC18F458is selected as the core microcontroller of the motor-driven sub-modules to complete the motor drive control by detecting four motors voltage, current, temperature, phase position signal and speed. Data exchange between the central controller and every sub-module based on CAN bus technology conforms to the design concept of the vehicle network control.The motor-driven part adopts the double-loop control of permanent magnet brushless DC motor. The circuit of energy feedback is designed based on braking energy recovery theory, braking energy is gathered through the super capacitor. In the electronic differential control part, the target speed of the motor would be calculated according to the Ackermann-Jeantand differential model. Then the control of whole vehicle is implemented by speed control model.Finally, a large number of calibration and experiments are done based on experimental platform of EV driven by in-wheel motors in the laboratory. The results show that network communication between every module works normally, the system runs with good differential control characteristics under no load and achieves the desired target. Parameters calibration and control strategies need to be improved in the future road experiments.