Baps

Developed at the Delft Biorobotics Lab, Baps is an affordable autonomous 3D Walking robot that is known for its simple, low-power design equipped with phasic actuation along with stiffness control. The development of this autonomous robot was funded by Technology Foundation STW. Also known as the Biped with Adjustable Pneumatic Springs, Baps uses artificial muscles with mechanical power consumption less than that of a human's muscles.

Baps is based on the principle of ballistic walking, which involves walking with free, unpowered movements. Although the ballistic principle provides benefits such as low power consumption as well as simple mechanical design, its major limitation is that the walking motion depends on the system's inherent properties, including rigidity of the components as well as mass distribution. In Baps, McKibben artificial muscles are used to overcome this problem. These artificial muscles are made of special rubber tubes inside sleeves that get stiffer as the air pressure inside them increases. In addition to allowing the robot to comfortably walk on flat surfaces, the McKibben muscles change the legs’ natural frequency by decreasing or increasing the basic pressure. As a result, Baps is capable of walking more quickly or slowly.

Manufacturers have used two reflex actions for controlling the muscles of the biped robot. As the swinging motion initiates, the muscles (analogous to the human leg along with hip extensors) are activated. Moreover, the pneumatics aim at ensuring that the stance leg becomes stiff right before the swinging leg’s foot touches the ground. Apart from being equipped with the muscle reflexes, Baps utilizes an additional control level, which helps it deal with disturbances associated with the pattern of normal walking. The control level relies on an onboard computer for power processing. Overall, Baps is an affordable autonomous robot that is known for its simple, low-power design. The robot’s low weight even makes it inherently safe in interaction with users.