Trajectory design for a walking robot

Hy everybody! I want to design a trajectory for the walking robot that i’m creating. I have an array of 100 waypoints that the “foot” has to follow (3x100 points). I don’t want to define a fixed time trajectory because i want to design it in a way that if i provide (in real time),using a GUI, different values of speed i can obtain faster or slower trajectory. Also when i reach the last point of my array, i have to be ready to do another “foot-step” and so to repeat the trajectory. How i can do that in simulink? Thank u, Andrea ;)

Answer 1

[Gowtham]

Hello Andrea,

It is my understanding that you are working on creating a real-time trajectory for a robot using the waypoints that are available to you.

This can be achieved by using tools from the Robotics System Toolbox and a Simulink model.

For a sample demonstration of the above process, kindly refer to the following steps:

1. Start by defining your desired waypoints, which should consist of a point matrix.
2. Use the ‘waypointTrajectory’ System object from the Robotic System Toolbox to generate the specific trajectory.
3. The 'release' function is available to allow for the modification of any properties within the 'waypointTrajectory' object.
4. Within your Simulink model, incorporate a MATLAB Function Block to compute and output the next waypoint, considering the 'speed' input parameter for the function.
5. To enable the robot to repeat the trajectory from the beginning after reaching the final waypoint, you can include a conditional check within the MATLAB Function Block.
6. The speed input can be given in the Simulink model using the Slider block.
7. Finally, connect the output of the MATLAB Function Block to the appropriate blocks or systems that control your robot's foot movement.

Kindly refer to the following MATLAB Documentation(s) for further information on how to use the mentioned functions:

• ‘waypointTrajectory’: https://www.mathworks.com/help/robotics/ref/waypointtrajectory-system-object.html
• ‘release’: https://www.mathworks.com/help/fusion/ref/waypointtrajectory-system-object.html#mw_f148e3a4-b09a-4af8-81fb-e86297d24b01
• MATLAB Function Block: https://www.mathworks.com/help/simulink/ug/what-is-a-matlab-function-block.html
• Slider Block: https://www.mathworks.com/help/simulink/slref/slider.html
• Robotics System Toolbox: https://www.mathworks.com/help/robotics/index.html

Hope this helps.

Best Regards,

Gowtham