A new approach to the calibration problems of three-dimensional laser scanners

Synchronized laser scanners are the most popular 3D image capture systems for industrial applications. The accuracy of the scanned picture is a key factor of the complete system. In this paper, a new mathematical description of synchronized laser scanners will be presented, which is necessary to the developed calibration method. The mathematical model is based on the geometrical design of the triangulation and it can make the application of scanners easier. The calibration method is working by tests on reference planes, which should be scanned and some reference points should be chosen on it. Due to the combined relations among the geometrical and system parameters, it is better - as shown - if the system parameters are estimated step-by-step by a linear error correcting method from the measured data and from the coordinates of the points on the reference planes. The new mathematical model allows simulating the function and the errors of the triangulation system easy. The error analysis of the system can help us to obtain important data from the model to design synchronized scanners

Designing and tuning a brake assistant for omnidirectional wheels

Although the invention of the special wheels that move omnidirectional vehicles dates back to the seventies, advances in mechatronics, and control technology keep them constantly on the drawing table of engineers working with mobile robots. The need for eliminating human error becomes ever so obvious when human operators are managing expensive and/or powerful machinery, as the cost of failure can be very high. Omnidirectional platforms are not immune to human error either, however due to their unique working principle they require customized methods. This article presents a trajectory controller for omnidirectional transport robots that is able to correct their trajectory during braking even when high disturbances are present. A method for tuning the controller to achieve a desired  behavior is presented. The results are demonstrated by simulation, in Modelica – Dymola environment

Simulation Methods for Traffic Control and Position Estimation of Mobile Robots

In this paper we present a simulation approach in the field of landmark-based mobile robot navigation. A method is shown to involve statistical traffic analysis for determining critical positioning accuracy limits in certain points of the environment. We also describe an algorithm to evaluate spatial uncertainties assuming a navigation strategy. This strategy uses dead-reckoning frequently updated by absolute position measurements. We have implemented a simulation software to check the effectiveness of the new algorithms. The methods and simulation results are explained through simple examples