Computer Animation of Modular Robotic Systems, page 2

There are numerous issues involved in the development of a modular and reconfigurable robotic system. The intelligence and decision making system that will deal with the inverse kinematics of a reconfigurable and possibly redundant system must be developed. A controller that can adapt to reconfiguration of the system under control must also be designed and built Indeed modularity must be incorporated into every aspect of the robot's design in order to have a truly modular and reconfigurable system.

A modular approach to robot design also provides many direct benefits to the computer animation of robot systems. The modular computer animation package builds graphical robots that are inherently reconfigurable to animate many different robot configurations performing a wide variety of tasks. Based on this package, the creation of each animation, is simplified to the extent that no graphics experience at all is necessary to quickly create high-quality animations. The performance of the computer animation is also increased because modularity allows many calculations to be done prior to beginning the actual animation sequence. 

Software - A software package has been developed to interactively assemble three -dimensional computer animations of robotic systems. This package was completely designed and implemented by the authors. It is written in the C programming language. One, two and three degrees of freedom joint modules and generic links are used as the basis of this modular and reconfigurable animation package. These modules may be assembled into a large class of robotic systems that include serial, parallel, mobile and hybrid configurations. The animated model is created by specifying which modules are used and how they are connected. The main menu bar is at the top of the screen and contains the options 'FILE', 'BUILD', 'RUN' and 'UTILITIES'. These menus are of the pull-down variety and are activated by positioning the cursor over the desired option and clicking the mouse button. The 'BUILD' menu is used to sequentially assemble the modules into the robotic structure. The building procedure relies on the idea of a drawing frame. The frame is translated and rotated to provide a local origin for each module. Each module is added to the robot model relative to this frame and may change the frame before adding the next module. In general each module uses six arguments that may move the drawing frame before a module is added and six arguments that may move the drawing frame after the module is added. The program calls these the input frames and the output frames, respectively. The modules also need to be scaled. The scaling parameters are the diameter, length, height, width etc. In the 'BUILD' menu are the choices 'add joint', 'add base', 'add link', 'end effector', 'environment' and 'parallel'. The parallel dialogue box asks for six arguments that specify the position and orientation of a branching chain relative to the current position of the drawing frame. The other dialogue boxes will ask for a more specific choice of which link, joint, base, end effector or object in the environment is to be built with. Modules are added relative to the position and orientation of the drawing frame active when the build option was selected. The parallel option in the menu tells the program that the current serial chain is branching. The parallel dialogue box asks for six parameters that will specify the position and orientation of the branching frame relative to the current drawing frame. The program, will continue to add modules to the branching chain until an end effector is added to the chain. The end effector is a signal to the program to terminate the current chain and return to the drawing frame that was active when the parallel option was invoked. Terminating the first chain with an end effector will cause the initial frame to become active. The parallel option can also be used to create multiple robots operating in the same environment. Next Page ->