The SILO4 Walking Robot: Simulator

The simulation of the SILO4 robot motion has been created through the Yobotics! Simulation Construction SetÓ software package, which permits easy and quick creation of robot simulations. The resulting simulation shows a 3D motion of the robot and at the same time numerical and graphical simulation data is displayed (see next figure). Any control variable can be modified along the simulation and all data can be exported and imported to/from MATLAB files.

The simulation has been programmed in Java and it is organized into the following classes (see next figure). 

• Simulation class: Contains functions for setting the parameters of the simulation, such as the integration time step, camera position, variables initially plotted in the graphs, etc. It also relates the simulation with the SILO4 robot.
• Robot class: Defines the geometry and dynamics of the robot. The robot consists of a tree of joints and links with shape, colour, mass and inertia. Some ground contact points are defined in the robot and calls to the ground contact model, ground profile and controller are performed.
• Controller class: Here, the control algorithm for the motion of the robot is programmed. The SILO4 walks in a two-phase discontinuous gait, which is controlled by a state machine, where swing and support phases of the robot legs are selected. Leg trajectory generation is also programmed, where the foot follows a straight line, and joint trajectories are PD controlled.
• Ground Profile class: It defines the shape of the ground, i. e. planar, inclined, uneven, etc.
• Ground contact model class: Here, the dynamics of the robot/terrain interaction are modelled. The model used for the SILO4 simulation is a spring-dumper in the x, y, z directions.

The software for running the SILO4 simulation is completely free. To run the SILO4 simulation one just has to follow some steps:

1. Download and Install Jbuilder6, a Java development program.
2. Download and Install the Yobotics! Simulation Construction Set (free 1 month trial evaluation). Follow carefully the installation guide that can be also downloaded from the same site.
3. Unzip the SILO4_simulation package.
4. Double-click the Silo4.jpx project file.
5. Enjoy!

Home