State Estimation and Coordinated Control for Distributed Electric Vehicles
The state observation method for distributed electric drive vehicle described in Chap. 3 can provide the support for the dynamic control of vehicle.
The distributed electric drive vehicle is equipped with multiple driving wheels without mechanical connection, and the property of distributed drive
can ensure the control system to perform independent control allocation on the driving force of each wheel. The reasonable utilization of properties of distributed electric drive vehicle is significant to the comprehensive optimizing of dynamic control property of full vehicle on the premises of meeting driversí requirements and ensuring safety. According to the properties of the distributed electric drive vehicle, this dissertation designed a complete set of coordinated control system for distributed electric drive vehicle, including three technologies, i.e. determination of vehicle dynamic demand target, driving force control allocation, and motor property compensation control. For the determination of vehicle dynamic demand target, tracing of desired side slip angle and desired yaw rate is taken as the lateral stability control target. The direct yaw moment method is used for controlling the lateral stability of vehicle, so as to enhance the safety of vehicles. The expected yaw rate and side slip angle are made by the non-linear vehicle model, and the expectation value is taken as the lateral stability control target, and the scheme which comprehensively considers the Ŗ-Ŗ?
phase diagram and road surface adhesion coefficient is put forward when the weights of the yaw rate and side slip angle are adjusted. For driving force control
allocation, many limitation conditions required by control allocation of distributed electric drive vehicle were taken into consideration, including motor driving capacity, motor failure condition, road surface adhesion condition, etc. When the allocation is optimized, the motor utilization rate is defined for describing the utilization condition of distributed electric drive vehicle, and the optimum objective function is defined to comprehensively reduce the utilization rate of all motors and protect the failed motor. When optimizing, the designed objective function is solved by the functional collection method, so as to further perform control allocation on the driving force of each wheel. For motor property compensation control, the dynamic response error and steady-state response error between different motors are taken into consideration, the self-adaptive control method is adopted for correcting the dynamic response and steady-state response properties of all motors, then the responses of all motors are approximately consistent, and the command on control allocation layers is accurately completed in real time. The three technologies respectively determine the demand target of full vehicle, the driving force of each wheel is subject to control allocation, the moment command on driving wheels is made to execute the moment allocation value of each wheel, and then a complete set of coordinated control system is formed, so as to meet the demand target of full vehicle.
- Paperback: 187 pages
- Publisher: Springer Berlin Heidelberg
- Language: English
- ISBN-10: 978-3-662-48708-2_4
- ISBN-13: 978-3-662-48706-8