CAN Network Based Longitudinal Velocity Measurement Using Accelerometer and GPS Receiver for Automobiles

A design of Controller Area Network (CAN) based longitudinal velocity measurement system using MEMS accelerometer and GPS receiver is presented. CAN is a serial communication protocol which efficiently supports distributed control system with high level of security. The system consists of a master node and a slave node built around LPC1768 and LPC2129 microcontrollers respectively. The master and slave nodes are linked with CAN bus. The slave node gets velocity data from GPS receiver and transfers to the master node. The master node samples the accelerometer output, and saves the sampled data and the velocity data received from the slave node on a microSD card. A LabVIEW program has been developed to study the measured parameters in offline by applying a Kalman filter and computing the estimate of longitudinal velocity. Typical measurements with the present system in a standard driving maneuvers and computation of estimate of longitudinal velocity using the LabVIEW program are presented. The measurement system produces comparable results with the conventional meter.