Heuristic reduction of gyro drift in gyro-based vehicle tracking

This paper pertains to the reduction of measurement errors due to drift in rate gyros used for tracking the position of moving vehicles. In these applications, gyros and odometry are often used to augment GPS when GPS reception is unavailable. Drift in gyros causes the unbounded growth of errors in the estimation of heading, rendering low-cost gyros almost entirely useless in applications that require good accuracy for more than just a few seconds or minutes. Our proposed method, called "Heuristic Drift Reduction" (HDR), applies a unique closed-loop control system approach to estimate drift in real-time and remove the estimated drift instantaneously from the gyro reading. The paper presents results of experiments, in which a gyro-equipped car was driven hundreds of miles on highways, rural roads, and city streets. HDR reduced the average heading error over all of these drives by one order of magnitude.