OpenSHC: A Versatile Multilegged Robot Controller

Abstract

Multilegged robots have the ability to perform stable locomotion on relatively rough terrain. However, the complexity of legged robots over wheeled or tracked robots make them difficult to control. This paper presents OpenSHC (Open-source Syropod High-level Controller), a versatile high-level controller capable of generating gaits and poses for quasi-static multilegged robots, both simulated and with real hardware implementations. With full Robot Operating System (ROS) integration, the controller can be quickly deployed on robots with different actuators and sensor payloads. The flexibility of OpenSHC is demonstrated on the 30 degrees of freedom hexapod Bullet, analysing the energetic performance of various leg configurations, kinematic arrangements and gaits over different locomotion speeds. With OpenSHC being easily configured to different physical and locomotion specifications, a hardware-based parameter space search for optimal locomotion parameters is conducted. The experimental evaluation shows that the mammalian configuration offers lower power consumption across a range of step frequencies; with the insectoid configuration providing performance advantages at higher body velocities and increased stability at low step frequencies. OpenSHC is open-source and able to be configured for various number of joints and legs.

Design, Construction, and Rough-Terrain Locomotion Control of Novel Hexapod Walking Robot With Four Degrees of Freedom Per Leg

“…Among a wide range of control approaches, foothold adaptation based on online force estimation using direct measurements of the joint forces by dedicated sensors [42], [49]- [51], or based on the estimation of joint torques using servomotors current readings [45], [52] are utilized in existing solutions. However, in our design choices, we have been limited to the usage of the Dynamixel AX-12A servomotors that do not directly provide the information about the motor current, and thus the joint torque.…”

“…Hence, given the control cycle period T con there are n sp = t g n −1 gp T −1 con individual poses on the path between g p l curr and g p l new . We have selected the positive amplitude of the sine wave as the desired leg path for its smooth profile, although more elaborated swing path can be designed considering the leg dynamics and terrain characteristics, e.g., as in [25], [52], [59]; however, such a trajectory optimization requires exteroceptive sensing and is out of the scope of the presented design of the HAntR. Hence, the immediate foottip pose g p l at the control cycle k is computed as…”

The Probe: Design and Development of a Large Hexapod Robot

“…They demonstrated that a series-elastic actuated hexapod robt climbed over different obstacles. Tam et al with CSIRO's Robotics and Autonomous Systems Group developed Opensource Syropod High-level Controller (OpenSHC) which is a controller for multilegged robots to generate statically stable gaits [19]. For a hexapod robot, Belter and Skrzypczyński [20] developed feasible gait patterns using evolutionary algorithm with dependencies inspired by typical insect behaviour.…”