Anti-lock braking system based on FlexRay protocol
The anti-lock braking system is nowadays a part of almost every vehicle. This system increases safety of the people sitting in the vehicle at the moment of stopping on a slippery or unstable road surface. The point is to assure a good controllability of the vehicle even if the wheels are in slip. In order to work properly, the anti-lock braking system needs to have actual information about the rotation of every single wheel. And the up-to-dateness and certainty of an accurate information is the primary criterion of an appropriate performance. Currently, the information about the frequency of wheel rotation is being transmitted via the current loop. This solution needs a lot of wiring, which means increased purchase costs. This paper describes a method, where the information from the rotation sensors of the wheels are transmitted into the control unit through the FlexRay bus. Additional wireless acceleration sensors located on the wheel are used to improve the ABS performance.
Modelling and analysis of flexray protocol in VHDL
In an automotive industry, more complex functions are integrated to vehicles, this brings about the requirement for more quicker and dependable in-vehicle systems. These functions are controlled and monitored by different Electronic Control Units (ECU). Time-triggered protocols like Flexray have been making progress as the standard high-speed reliable communication in the automotive industry, marking a shift away from the event-triggered system access used in Controller Area Networks (CAN). Flexray offers superior flexibility, reliability and a high-speed communications protocol. It was devised by automotive manufacturers and semiconductor vendors. Flexray delivers fault tolerant communication and time triggered bus between various electronic devices for automotive applications. Flexray is protocol designed to provide large cluster of data to be exchanged in real time and with great dependability between ECUs, sensors and actuators. This work deals with Modelling and analysis of flexray protocol in VHDL language. Xilinx and Modelsim simulation tools are used to analyze the results. Further, FPGA can be utilized to attain the reconfigurable parallel design so that in automotive communication this system gets higher reliability and speed.
Semi-active dampling in automotive systems: design-by-simulation
The article describes the design and implementation of semi-active suspensions for trucks. The main objective of semi-active suspension design is decreasing road damage. The feedback laws for the semi-active dampers are designed by simulation and parameter optimisation. The performance predicted by the simulation experiments is verified for two real vehicles - a platform truck and tractor semi-trailer combination. The simulation experiments as well as the field measurements indicate the semi-active damping as a concept for producing more road friendly heavy-duty vehicles.