The ?Differential Drive and Global Positioning Blockset? is the tool which can be used with Simulink® for modeling, designing, and simulation of the dynamics of a type of vehicle robots called differentially driven vehicle robot (robot which uses differential steering technique for locomotion). This tool carries the blocks with built-in Global Positioning algorithm (related to dead-reckoning), which are useful in finding out the current position and heading of the vehicle robot.
This blockset will allow the scientists and engineers to build and simulate their models of vehicle robot using differential drive steering method according to their own design and specifications, and will enable to visualize the results in the form of model-driven animation.
The blockset has seven different blocks: The PMDC Motor block, Gearbox block, Motor Driver block, Mechanical Dimensions block, Positioning block, Dual PID block and the Animation block. These blocks constitute a complete set of components by using which a complete model of a differentially driven vehicle robot can be built. The resulting model can be tested in the form of model-driven animation and the parameters of the model can be varied from the GUI provided in the animation window on the fly.
The PMDC Motor block is a complete model of a Permanent magnet DC motor. A user can put its own parameter values of DC motor which he wants to use in the actual model of robot. This model also simulates the applied load on the motor shaft.
Gearbox block is simulated gear-train whose gear-ratio can be set according to user specifications.
Motor Driver block behaves like the practical motor driver circuits, using whose logical inputs the direction of PMDC motor can be reversed, and break can be applied.
By including the Mechanical Dimensions block in the model user can implement the model of a differentially driven vehicle robot whose dynamic behavior will largely depend on the mechanical dimensions like drive wheel radii, robot platform length and width, and location of drive wheels in robot platform.
Positioning block calculates the current position of the vehicle robot turning center in Global Coordinate System.
Dual PID Control block provides a pair of PID controllers for each motor of the differential drive system for speed control.
Finally, the Animation Block generates animation of the designed differentially driven vehicle robot according to model specifications. The animation window also provides the GUI in the form of different sliders using which the angular velocities of the wheels can be varied, and also the direction of the motors can be reversed during simulation.