HEV Instrument Design Based On CAN Bus

In hybrid vehicles, some new components are added, for example, the vehicle controller, batteries, motors and other special and critical parts, the operation conditions of these components play an important role in traffic safety, and at the same time, traditional vehicle information, such as speed, engine speed, water temperature, fuel and other information are also crucial, therefore, the development of instrument which not only show vehicle working state, battery SOC and other specific information about HEV, but also display traditional vehicle information is essential.The main contents of this paper are as follows:First, an overall design method of instrument system was put forward, the instrumentation system is divided into two parts according to the input and output signals, CAN signals, A/D signals and I/O signals are input ones, and these collected signals will be processed in the single chip, and then be outputted. There are two ways for the output of signals, one is to be showed in traditional instruments, for instance, the vehicle speed, engine speed, etc., the other are displayed in the LCD instrument, for example, the HEV working status and annex information.Secondly, the hardware design of instrument was introduced, including the selection of host controller, CAN transceiver chip circuit design, traditional instrument design methods, and external circuit design of display chip are elaborated, also, a number of anti-jamming hardware design methods are introduced. Finally, the software design, based on embedded operating system OSEKturbo, was introduced. Including the need for real-time operating system, OSEK/VDX norms introduction and norms of OSEKturbo, and also elaborated on the task demarcation, scheduling in the instrument control software, as well as interruption settings. At the end, LCD display method was introduced.In short, this paper studied on CAN bus, real-time operating system and the instruments, and a HEV instrument design method was put forward, along with the hardware and software design process. The system has been successfully applied on a HEV demo car.