Bian Yongming

A method for response time computation in FlexRay communication system

As a new communication protocol, FlexRay, which is supported by FlexRay Consortium consisting of many biggest automobile companies, is becoming a de-facto standard for automobile communication system. This paper provides a timing analysis of the FlexRay communication cycle, including static (ST) segment and dynamic (DYN) segment, and proposes a methodology to calculate the worst-case response time of static segment and dynamic segment respectively, taking the communication delay and all the possible factors into account. Besides, this paper presents a way to determine whether messages in DYN segment could be transmitted in the current cycle based on the some related work. Finally, a model which can be implemented in FPGA for application is created to simulate the ideal situation and the real node state; the behavior simulation result and post-route simulation result are compared and analyzed to demonstrate the preceding theory.

Research on Inverted Pendulum Network Control Technology

The research of inverted pendulum and network control system are combined in this paper. Firstly, the stability control of inverted pendulum is discussed. Secondly, network control system is introduced and the structure of inverted pendulum network control system is analyzed. Finally, the simulation model of inverted pendulum network control system is established by True Time simulation module. Through the model, some simulation and analysis have been made on inverted pendulum network control system.

Variable frequency hydraulic speed control system based on CANopen

This paper combined hydraulic transmission, frequency speed control and CAN bus communication together to establish variable frequency hydraulic speed control system. Inverter, PLC, sensors communicated with each other with CANopen protocol in the system. The system could vary speed in a wide range, control the motor speed precisely and improve the response time and stability of hydraulic system. The variable frequency hydraulic speed control test platform was built, two cylinders pulling reverse was adopted as a way of loading to test the systems speed control performance, we found that the motor response time equaled to the inverter acceleration or deceleration time. The actuator response time mainly depended on the motor response time, the hydraulic pump output flow and cylinder size. Low-frequency performance of the system was analyzed, the minimum static frequency under different loads of the system was obtained through experiments.