Second CONRO prototype - SOFTWARE based on centralized control

Permission to use these images and movies is granted free of charge as long as the credit line "USC Information Sciences Institute" is included.

This page shows examples of the work done by Andres Castano and Ramesh Chokkalingam in the area of control of multiple modules using a remote host control. In this control, a large computer performs all the high level functions while the local processors in the modules of the robot perform the local tasks, mainly communication and position control of the motor. In essence, a master-slave approach.

Implementation mov (4.7 Mb), mpg (4.7 Mb).

Many of the pictures and movies will show cables protruding from the modules. These are power cables that we put in the module to reduce our operation costs: each module uses 2 $6 batteries and they last for 35-40 mins; a hexapod needs 9 modules so it costs $100 to power it and thus, an experiment that lasts 5 hours costs around $800. Therefore, for all tests we are powering the robots with an external power supply. However, as the video shows, each module is self-contained and doesn't need the external power supply.

All snake robots can perform this type of sinusoidal motion... (mov (10 Mb), mpg (8.8 Mb)).

.. but have you ever seen a snake robot that can move WHILE its being assembled?.. have a look. (mov (28 Mb), mpg (20 Mb)).

These are the first experiments making sinusoidal motions with the new modules. The motions of this snake are slow when compared with those of the first prototype. However, consider that now each module is an independent robot and the overall motion is now generated as a the coordinated action of a chain of robots.

Push up 1: Left legs first, right legs last (mov (10.7 Mb), mpg (4.5 Mb)).
Push up 2: Front legs first, rear legs last (mov (9 Mb), mpg (3.9 Mb)).

Push ups.. two different hexapod stand up and lay-down maneuvers. The first one attempts to move all the legs of one side of the hexapod before moving the legs of the other side. The second one attempts to move first, the frontal legs, then the legs at the center and finally the rear legs. In the movies, you can notice that these maneuvers are not executed exactly due to communication delays between the modules.

4-legged robot that stands up, walks by moving its hands and then lays down (mov (24 Mb), mpg (13 Mb)).

Same gait, different background and gait speed that shows the details of the motions. (mov (60 Mb), mpg (28 Mb)).

Finally, some locomotion. This is a 4-legged robot that stands up, walks a little bit and then lays down. A cross on the floor serves as a reference for the motion of the robot. The robot is composed of 6 modules (four modules for the legs and two modules for the spine). The gait is a little similar to a gorilla gait, walking on its knuckles. The robot moves its shoulders and hands but it doesn't move its spine.

4-legged robot that stands up, walks swinging its spine and then lays down (mov (26 Mb), mpg (16 Mb)).

This gait is based on those of reptiles and fish (e.g., see the work of Hirose or Tony Lewis). The robot advances by contorting its spine. The robot moves its shoulders and spine but it does not uses its hands.

hexapod that stands up, walks swinging its spine and then lays down (mov (63 Mb), mpg (31 Mb)).

A movie of the haxapod moving by contorting its spine. The files are pretty large so you better have a fast connection if you want to see them.

A 9-module snake executing a traveling wave gait (mov (23 Mb), mpg (15 Mb)).

A 9-module snake going through the motions of a traveling wave. In this particular setup, the snake does not advance very fast because of the low friction between the snake and the carpet.

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