Commande par supervision de systemes mecatroniques via Internet.

摘要

The research project presented in this document deals with the supervisory control of mechatronic systems via the Internet. Its objective is to propose, design and test a web application architecture based on open standards allowing this type of control by studying a concrete example. The proposed approach is based on a dynamic web application using Java 2.0 Enterprise Edition (J2EE), a dynamic web page using Javascript and the high-level communication protocol Asynchronous JavaScript and XML (AJAX). In addition, in order to be able to control mechatronic systems remotely, a communication architecture has been implemented. It includes inter-chip communications performed by the Serial Peripheral Interface (SPI), wireless communications conducted by a proprietary solution using the Gaussian Frequency-Shift Keying (GFSK) modulation method, communications between an electronic board and a PC realized by Universal Serial Bus (USB), and communications between a PC acting as a web server and other computers acting as clients with Transmission Control Protocol / Internet Protocol (TCP / IP). To experiment with the proposed architecture, a mechatronic system consisting of a two-wheeled mobile inverted pendulum robot was developed and a remotely generated trajectory tracking problem has been considered. The mechanical design of this robot consists of a body with a shaft and two wheels, each driven by a DC motor through a gear box. The body and wheels were designed using CAD software and were manufactured and assembled at Ecole Polytechnique de Montreal. The electronic system of the robot consists of a microcontroller, two optical encoders used for measuring the positions of the wheels, a two-axis accelerometer and a gyroscope used to measure the tilt angle of the robot, two H-bridge chips used for controlling the DC motors, a liquid crystal display module, a chip for wireless communication with a computer, a set of batteries and two voltage regulators used as a power supply.A user interface in a web page to allow an operator to generate a trajectory that the robot must follow has been created. It includes a visual simulation carried out by a JavaScript in the web page in which a virtual model of the robot anticipates the behavior of the real robot, and where it is possible to see the evolution of the desired trajectory as well as the actual path taken by the robot.Experiments were conducted to assess the validity of the mathematical model, the performance of the controllers and the operation of the remote control system. These experiments demonstrate the validity of the model developed, the ability of the controller designed by the Hinfinity method to reject external disturbances, the ability of the visual simulation to anticipate the behavior of the robot despite the presence of communication delays on the network and the proper functioning of the path-tracking algorithm.The balancing robot designed presents several challenges including the fact that it is an unstable system and therefore requires a controller to stabilize it and maintain its balance. In order to design this controller, the dynamics of the robot has been analyzed and a mathematical model was developed in the form of linear state-space models. Filtering algorithms to obtain good estimates of the states despite the presence of noise in the sensors' signals were also implemented. Control laws to control the tilt angle, the linear displacement and the heading angle of the robot were synthesized using the pole placement technique in the first place and then using the H infinity method to minimize the system's sensitivity to external disturbances. Finally, to ensure that the path actually taken by the robot follows closely the desired trajectory, a path-tracking controller has been designed. The algorithms for filtering and control have been implemented numerically in a realtime software executed by the microcontroller of the robot.