Liang-Liang Yang

Self-localization method using a single omni-directional camera based on landmark positions and arrangement

This paper proposes a self localization method for autonomous vehicles with just a omni-directional camera. Proposed method uses positions and arrangement of landmarks which are preliminarily obtained, and estimates the position of omni-directional camera based on the cosine formula. Also measurements of distances between the camera and the landmarks are not required, which are needed for conventional self-localization method but becomes the major reason of estimation errors. So, this method can obtain a large advantage to avoid the estimation errors due to the measurement error of the distance between camera and landmarks. The geometric nonlinear simultaneous equations consists of the cosine formulas are solved by recursive least squares method. Performance and accuracy are indicated by the results of simulations.

Calibration of an auto-steering system using a line-type laser and a camera without necessary of running the vehicle

An auto-steering system is a system that can directly control the steering wheels of a wheel-type vehicle without any directional manipulation by the drivers of the vehicle. This kind of technology is important for the automation of the off-road vehicles for agriculture. In this study, an auto-steering system was proposed by using a stepping motor and a hydraulic torque generator, for the rotation angle of the former can be easily controlled while the latter can provide a higher torque. And the stepping motor was utilized to control the torque generator. In addition, a line-type laser diode was utilized to show the direction of the front wheel. A color camera was adopted for detecting the steering angle of the front wheel. And an image processing method was developed to measure the steering angle. The results of the simulation experiment indicate that the steering angle could be detected with an accuracy of less than 0.2 deg using the laser-camera system. And the relationships of the input of the command to the motor and the output of the steering angle was calibrated by the proposed method.